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Dialectica

St John of Damascus, tr. Chase, 1958

The Philosophical Chapters

Preface

THE MOST LOWLY MONK and priest John to the most saintly and honored of God, Father Cosmas¹ the most holy Bishop of Maiuma, greetings in the Lord.

Being fully conscious of the limitations of my intelligence and of the insufficiency of my language, your Beatitude, I have hesitated to undertake a task exceeding my capabilities and to presume to enter into the Holy of Holies like some bold and foolhardy person, for I am wary of the danger that threatens those who attempt such things. The divine Moses, the lawgiver, withdrew from all sight of human things and abandoned the turbulent sea of life. He purified the eye of his soul by wiping away every material reflection, and only then did he become fit to receive the divine vision. Only then was he found worthy to behold the benevolent condescension of God the Word and His marvelous appearance in a bush and in immaterial fire, which, while it enkindled and burnt the tree and changed it into His splendor, did not consume or destroy it or alter its proper nature. He was the first to learn the name of HIM WHO IS and who truly is super-essential, and he was entrusted by God with the leadership of his own countrymen. Yet, if he considered himself as ‘having impediment and slowness of tongue’—² and thus unable publicly to execute the divine will and to be appointed a mediator between God and man—then how am I, who am defiled and stained with every sort of sin, and who bear within myself the tumultuous seas of my conjectures, and who have purified neither my mind nor my understanding that they may serve as a mirror of God and His divine reflections; how am I, who have not sufficient power of speech to express such concepts, to utter those divine and ineffable things which surpass the comprehension of every rational creature? With these considerations in mind I have hesitated to undertake this book. Besides this, to tell the truth, I feared to accede to the request, lest I should incur ridicule on the double count of ignorance and of folly. The latter is quite serious, for the charge of ignorance may be excused—provided the ignorance is not from laziness; but to add to ignorance a false pretension to knowledge is serious, blameworthy, and quite unpardonable, and it is a sure sign of a greater, if not the greatest, ignorance. On the other hand, however, the fruit of disobedience is death, while the humble and obedient man, because he has shown himself to be an imitator of Christ, is led from the lowest place to the highest. He receives from God the grace that illuminates, so that in the opening of his mouth he is filled with the Spirit. He becomes purified in heart and enlightened in understanding. When he opens his mouth, he receives the power of speech and has no concern as to what he shall say, because he is an instrument of the Spirit speaking within him. Therefore, in obedience through you to the Christ who in you exercises the pontifical office, I bow to your request and open my mouth, being confident that through your prayers it will be filled with the Spirit and that I, taking so much as He shall give and speaking this aloud, shall utter eloquently the fruit not of my own understanding but of the Spirit who giveth wisdom to the blind.

First of all I shall set forth the best contributions of the philosophers of the Greeks, because whatever there is of good has been given to men from above by God, since ‘every best gift and every perfect gift is from above, coming down from the Father of lights.’³ If, however, there is anything that is contrary to the truth, then it is a dark invention of the deceit of Satan and a fiction of the mind of an evil spirit, as that eminent theologian Gregory once said.⁴ In imitation of the method of the bee, I shall make my composition from those things which are conformable with the truth and from our enemies themselves gather the fruit of salvation. But all that is worthless and falsely labeled as knowledge⁵ I shall reject. Then, next, after this, I shall set forth in order the absurdities of the heresies hated of God, so that by recognizing the lie we may more closely follow the truth. Then, with God’s help and by His grace I shall expose the truth—that truth which destroys deceit and puts falsehood to flight and which, as with golden fringes, has been embellished and adorned by the sayings of the divinely inspired prophets, the divinely taught fishermen, and the God-bearing shepherds and teachers—that truth, the glory of which flashes out from within to brighten with its radiance, when they encounter it, them that are duly purified and rid of troublesome speculations. However, as I have said, I shall add nothing of my own, but shall gather together into one those things which have been worked out by the most eminent of teachers and make a compendium of them, being in all things obedient to your command. But I beseech you, Honored of God, to be indulgent with me, who have been obedient to your commands, and, receiving my obedience, to give me in return of the abundance of your prayers.

On Knowledge

NOTHING IS MORE ESTIMABLE than knowledge, for knowledge is the light of the rational soul. The opposite, which is ignorance, is darkness. Just as the absence of light is darkness, so is the absence of knowledge a darkness of the reason. Now, ignorance is proper to irrational beings, while knowledge is proper to those who are rational. Consequently, one who by nature has the faculty of knowing and understanding, yet does not have knowledge, such a one, although by nature rational, is by neglect and indifference inferior to rational beings. By knowledge I mean the true knowledge of things which are, because things which have being are the object of knowledge. False knowledge, in so far as it is a knowledge of that which is not, is ignorance rather than knowledge. For falsehood is nothing else but that which is not. Now, since we do not live with our soul stripped bare, but, on the contrary, have it clothed over, as it were, with the veil of the flesh, our soul has the mind as a sort of eye which sees and has the faculty of knowing and which is capable of receiving knowledge and having understanding of things which are. It does not, however, have knowledge and understanding of itself, but has need of one to teach it; so, let us approach that Teacher in whom there is no falsehood and who is the truth. Christ is the subsistent wisdom and truth and in Him are all the hidden treasures of knowledge.⁶ In sacred Scripture let us hear the voice of Him who is the wisdom and power of God the Father,⁷ and let us learn the true knowledge of all things that are. Let us approach with attention and in all sincerity and proceed without letting the spiritual eye of our soul be dulled by passions, for even the clearest and most limpid eye will hardly enable one to gain a clear view of the truth. ‘If then the light that is in us (that is to say, the mind) be darkness: the darkness itself how great shall it be!’⁸ With our whole soul and our whole understanding let us approach. And since it is impossible for the eye that is constantly shifting and turning about clearly to perceive the visible object, because for clear vision the eye must be steadily focused upon the object observed, let us put aside every anxiety of the mind and approach the truth unhampered by material considerations. And let us not be satisfied with arriving speedily at the gate, but rather let us knock hard, so that the door of the bridal chamber may be opened to us and we may behold the beauties within. Now, the gate is the letter, but the bridal chamber within the gate is the beauty of the thoughts hidden behind the letter, which is to say, the Spirit of truth. Let us knock hard, let us read once, twice, many times. By thus digging through we shall find the treasure of knowledge and take delight in the wealth of it. Let us seek, let us search, let us examine, let us inquire. ‘For every one that asketh, receiveth: and he that seeketh, findeth: and to him that knocketh, it shall be opened;’⁹ and ‘Ask thy father, and he will declare to thee: thy elders in knowledge and they will tell thee.’¹⁰ If, then, we are lovers of learning, we shall learn much,¹¹ for it is of the nature of all things that they may be apprehended through industry and toil, and before all and after all by the grace of God, the Giver of grace.

Furthermore, since the divine Apostle says: ‘But prove all things: hold fast that which is good,’¹² let us also find something in them worth carrying away and reap some fruit that will be of profit to our soul. For every craftsman has need, also, of certain things for the prosecution of his works, and it is also fitting for the queen to be waited upon by certain handmaidens. So let us receive such sayings as serve the truth, while we reject the impiety which exercised an evil tyranny over them. And let us not belittle that which is good. Nor let us use the art of rhetoric for the deception of simpler folk. On the other hand, although the truth stands in no need of the service of subtle reasonings, let us definitely use them to overthrow both those who fight dishonestly and that which is falsely called knowledge.¹³

And so, having invoked Christ as our Guide, the subsistent Word of God by whom ‘every best gift and every perfect gift’¹⁴ is given, let us make our beginning with such principles as are adapted to those who are still in need of milk. May those who happen upon this work have it as their purpose to bring their mind safely through to the final blessed end—which means to be guided by their sense perceptions up to that which is beyond all sense perception and comprehension, which is He who is the Author and Maker and Creator of all. ‘For by the beauty of his own creatures the creator is by analogy discovered,’ and ‘the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made.’¹⁵ Thus, if we apply ourselves in a meek and humble spirit to the attainment of knowledge, we shall arrive at the desired end. ‘You cannot believe in me,’ said Christ, who is the truth, ‘if you receive glory from men,’ and, ‘every one that exalteth himself shall be humbled; and he that humbleth himself shall be exalted.’¹⁶

What the Purpose of This Work Is

Anyone who begins something without a purpose is like someone fumbling in the dark, because he who labors with no end in view is entirely at loose ends. So, then, let us state at the very beginning what the proposed purpose of this work is, so that what we are to say may more easily be grasped. Our purpose, then, is to make a beginning of philosophy and to set down concisely in the present writing, so far as is possible, every sort of knowledge. For this reason let it be entitled a Fount of Knowledge. I shall say nothing of my own, but I shall set down things which have been said in various places by wise and godly men. First of all, then, it is best to know just what philosophy is.

On Philosophy

Philosophy¹⁷ is knowledge of things which are in so far as they are, that is, a knowledge of the nature of things which have being. And again, philosophy is knowledge of both divine and human things, that is to say, of things both visible and invisible. Philosophy, again, is a study of death, whether this be voluntary or natural. For life is of two kinds, there being the natural life by which we live and the voluntary one by which we cling lovingly to this present life. Death, also, is of two kinds: the one being natural, which is the separation of soul from body, whereas the other is the voluntary one by which we disdain this present life and aspire to that which is to come. Still again, philosophy is the making of one’s self like God. Now, we become like God in wisdom, which is to say, in the true knowledge of good; and in justice, which is a fairness in judgment without respect to persons; and in holiness, which is to say, in goodness, which is superior to justice, being that by which we do good to them that wrong us. Philosophy is the art of arts and the science of sciences. This is because philosophy is the principle of every art, since through it every art and science has been invented. Now, according to some, art is what errs in some people and science what errs in no one, whereas philosophy alone does not err. According to others, art is that which is done with the hands, whereas science is any art that is practiced by the reason, such as grammar, rhetoric, and the like. Philosophy, again, is a love of wisdom. But, true wisdom is God. Therefore, the love of God, this is the true philosophy.

Philosophy is divided into speculative and practical. The speculative is divided into theology, physiology, and mathematics. The practical is divided into ethics, domestic economy, and politics. Now, the speculative is the orderly disposition of knowledge. So, theology is the consideration of incorporeal and immaterial things—first of all, of God, who is absolutely immaterial; and then of angels and souls. Physiology, however, is the knowledge of the material things that are close at hand to us, such as animals, plants, stones, and the like. Mathematics is the knowledge of things which are in themselves incorporeal but which are found in corporeal beings—such, I mean, as numbers and musical notes, and, in addition, such things as geometrical figures and the movements of the stars. Thus it is that the logical consideration of numbers constitutes the science of arithmetic; that of the musical sounds, music; that of geometrical figures, geometry; that of the stars, astronomy. These stand midway between things that have bodies and things which have not, for, while number is in itself incorporeal, it is also found in material things, such as grain, for example, or wine, or any other such thing. Practical philosophy, moreover, is concerned with the virtues. It governs manners and shows how one must behave in society. If it lays down laws for the individual man, it is called ethics; but, if for the entire household, then it is called domestic economy; while, if for cities and countries, then it is called politics.

There are, however, some people who have endeavored to do away entirely with philosophy by asserting that it does not exist and that neither does any knowledge or perception exist. We shall answer them by asking: How is it that you say that there is neither philosophy, nor knowledge, nor perception? Is it by your knowing and perceiving it, or is it by your not knowing and perceiving it?. If you have perceived it, well, that is knowledge and perception. But if it is by your not knowing it, then no one will believe you, as long as you are discussing something of which you have no knowledge.

Since, then, there is such a thing as philosophy and since there is knowledge of things that are, let us talk about being. However, one should understand that we are beginning with that division of philosophy which concerns the reason and which is a tool of philosophy¹⁸ rather than one of its divisions, because it is used for every demonstration. So, for the present, we shall discuss simple terms which through simple concepts signify simple things. Then, after we have explained the meanings of the words, we shall investigate dialectic.

On Being, Substance, and Accident

Being is the common name for all things which are. It is divided into substance and accident. Substance is the principal of these two, because it has existence in itself and not in another. Accident, on the other hand, is that which cannot exist in itself but is found in the substance. For the substance is a subject, just as matter is of the things made out of it, whereas an accident is that which is found in the substance as in a subject. Copper, for example, and wax are substance; but shape, form and color are accidents. And a body is a substance, whereas color is an accident. For the body is certainly not in the color; rather, the color is in the body. Nor is the soul in knowledge; rather, knowledge is in the soul. Nor are the copper and wax in the shape; rather, the shape is in the wax and the copper. Neither is the body said to belong to the color; rather, the color to the body. Nor does the wax belong to the shape; rather, the shape to the wax. What is more, the color and the knowledge and the shape are subject to change, whereas the body and the soul and the wax remain the same, because substance is not subject to change. Also, the substance and the matter of the body is just one thing, while there are many colors. Similarly, in the case of all others things, the subject is substance, whereas that which is found in the substance as in a subject is accident.

Now, substance is defined as follows: Substance is a thing which exists in itself and has no need of another for its existence. Accident, however, is that which cannot exist in itself, but has its existence in another. God, then, is substance, and so is every created thing. God, however, even though He is substance, is super-substantial. There are also substantial qualities about which we shall have something to say.

Chapter 4 (variant)¹⁹

Being is the common name for all things which are. Now, this is divided into substance and accident. Substance is a thing existing in itself and having no need of another for existence, or, more precisely, that which is in itself and does not have its existence in another. Accident is that which cannot exist in itself, but has its existence in another. For the substance is a subject, just as matter is of the things made out of it, whereas an accident is what is found in a substance, as, for example, the body and its color. Certainly a body is not in the color; rather, the color is in the body. The body, then, is a substance, while the color is an accident. And it is the same way with the soul and prudence, for the soul is not in the prudence; rather, the prudence is in the soul. For this reason the body is not said to belong to the color; rather, the color to the body. Neither is the soul said to belong to the prudence; rather, the prudence is said to belong to the soul. The soul, then, is a substance and prudence is an accident. For, when the soul is taken away, its prudence is likewise taken away, because, if there were to be no soul, in what would the prudence be? However, when prudence is taken away, the soul is not necessarily taken away, for it is quite possible for a soul to be without prudence. And similarly with all others beings, that which has existence in itself and not in another is substance, whereas that which cannot exist of itself but has its existence in another is accident.

On Terms

Since it is our purpose to discuss every simple philosophical term,²⁰ we must first of all know with what sort of terms it is that philosophy is concerned. So, we begin our discussion with sound itself. A sound is either meaningless or it has meaning. If it is meaningless, then it signifies nothing; but if it has a meaning, then it signifies something. Then, again, a meaningless sound is either articulate or inarticulate. Now, that sound which cannot be written is inarticulate, whereas that which can be written is articulate. Thus, for example, the sound made by a stone or a piece of wood is an inarticulate and meaningless one, because it is not written and has no meaning. But such a sound, for example, as scindapsus is meaningless, yet articulate; for it can be written, although it does not mean anything, because there never has been a scindapsus, nor is there any now. Now, philosophy is not concerned with the meaningless sound, whether it be inarticulate or articulate. Again, the sound which has meaning is either articulate or inarticulate. Thus, an inarticulate sound which does have meaning is one such as the barking of dogs, because this sound, since it is the sound made by a dog, signifies the dog. It also signifies the approach of some person. It is, however, inarticulate, because it is not written. And so, philosophy is not concerned with this kind of sound either. Now, the articulate sound which has meaning is either universal or particular. Man, for example, is universal, whereas Peter and Paul are particular. It is not with the particular term that philosophy is concerned; rather, philosophy is concerned with that sound which has meaning, is articulate, and is universal, or, in other words, common and predicated of several things.

Again, such a term is either essential or non-essential. Thus, that term is essential which signifies the essence,²¹ or, to be more precise, the nature, of things. On the other hand, that is non-essential which signifies the accidents. For example: Man is a rational mortal animal. All of these terms are essential, for, should you remove one of them from the man, he would no longer be a man. If you say that he is not an animal, then, he is not a man. In the same way, if you say that he is not mortal, then he is not a man, because every man is at once animal, rational, and mortal. So, it is for this reason that these are called ‘essential,’ namely, that they complete man’s nature, so that without them it is impossible for the man to be a man. And similarly with every individual thing, those elements which go to make up the nature are called essential. Non-essential, however, are the accidents which can be or not be in the subject—in a man, say, or a horse, or some such other thing. Take the color white, for instance. Whether one be white or black, one is by no means any less a man. Consequently, these and the like are non-essential, which is to say, they are accidents, and they or their opposites may inhere in us.

The essential term either shows what a thing is or of what sort it is. Thus, for example, when we are asked what a man is, we say that he is an animal. Then, when we are asked what sort of animal he is, we say a living and a mortal one. So, the essential term, which shows of what sort something is, is called difference. That term which shows what something is either signifies several species, in which case it constitutes the genus, or it signifies several individuals differing from one another numerically but by no means specifically, in which case it constitutes the species. An example of the former, that is to say, of genus, is substance. Substance signifies both man and horse and ox, because each one of them is termed a substance and is such, although each one is a different species. An example of the latter, that is to say, of species, is man, because this term signifies several men, or, more exactly, all numerically different men. Thus, Peter is one and Paul is another, and they are not one but two. In species, however, that is to say, in nature, they do not differ, for all are called men and are such.

Consequently, there is that which is more particular and is numerically different, as, for example, Peter, an individual, a person, and a hypostasis. This signifies a definite person. For, when we are asked who this man is, we say that he is Peter. The term ‘other’ signifies the same thing, for Peter is one and Paul is another. Likewise the terms ‘he,’ ‘this,’ and ‘that’—these and such others as stand of themselves are applied to the individual. But that which includes the individuals is called species and is more general than the individual, because it does include several individuals. An example would be man, because this term includes both Peter and Paul and all individual men besides. This is what is called nature and substance and form by the holy Fathers.²² Now, that which includes several species is called genus, an example of which is animal, for this includes man, ox, and horse, and is more universal than the species. Moreover, both species and genus were called nature and form and substance by the holy Fathers. Furthermore, the species—that is, the nature and the substance and the form—does not produce something which is ‘other’ or something which is ‘of another sort,’ but rather ‘another’ of the same sort. Thus, we may say that by nature man is one thing and the horse another, but we may not say that they are one and another of the same sort. Speaking specifically, one says ‘this,’ and ‘it,’ and ‘that,’ and the like, all of which declare in what something is. The specific difference, however, constitutes something ‘of a different sort.’ Thus, the rational animal is a thing of one sort, while the irrational animal is something of another sort. The specific difference furthermore constitutes ‘such’ a thing, and ‘what kind’ of a thing, and ‘what sort’ of a thing. The non-essential term may be applied either to one species or to several. If it applies to one, then it is called a property. For example, the property of laughter belongs to man alone and that of neighing to the horse alone. If, however, it is to be found in several species, then it is an accident. Take whiteness, for example. This exists both in man and in the horse, and in the dog and many other species.

Now, these are the five terms to which every philosophical term may be reduced. Accordingly, we must know what each one means and what they have in common with one another and in what they differ. They are genus, species, difference, property, and accident.

Genus is that which is predicated—that is, affirmed and expressed (for to be predicated is to be affirmed in respect to something)—of several things that are specifically different in respect to what pertains to their essence. Species, on the other hand, is that in which something is, but which is predicated of several things that are numerically different. And difference is that which is predicated of several things specifically different in respect to their particular sort, and it is included in the definition as essential. This is that which cannot be and not be in the same species and cannot not be in the species to which it belongs. When present, it assures the existence of the species; when absent, the species is destroyed. Also, it is impossible for it and its opposite to be in the same species. Thus, for example, the rational cannot not be in man, because that which is irrational is not man. When it is present, it constitutes the nature of man; when it is absent, it destroys it, because that which is irrational is not man. Now, one must know that this is called essential, natural, constituent, and distinguishing, and specific difference, essential quality, and natural property of a nature. It is very properly said by the philosophers to be a difference which is presentative of the nature possessing it and most proper to this nature itself. A property is that which exists in one species and in the entire species, and which is always in it and is conversely predicable with it. Take, for example, the property of laughter. Thus, every man can laugh and everything that can laugh is a man. An accident is that in which something is of a certain sort and which is predicated of several things differing in species but which does not enter into the definition. It can either be or not be, for, when present, it does not assure the existence of the species, and when it is absent, the species is not destroyed. It is called a non-essential difference and quality. It is either separable or inseparable. That accident is separable which is sometimes present and sometimes absent in the same hypostasis, as would be sitting, lying, standing, sickness, or health. That, on the other hand, is inseparable which is not constituent of a substance because it is not found in the entire species, but which, nevertheless, when it does become present in some hypostasis, cannot be separated from it. Such, for example, are the having of a snub nose, being hook-nosed, being gray-haired, and the like. This inseparable accident is called a characteristic peculiarity. This is because such distinctiveness produces the hypostasis, which is to say, the individual—and an individual is that which subsists in itself of substance and accidents, is numerically distinct from the others of the same species, and does not signify what but whom. In the following we shall, with God’s help, learn more accurately about these things.

On Division

Division²³ is the first section of the thing. Thus, for example, the animal is divided into rational and irrational. Redivision is the second section of the same thing. For example, the animal is redivided into apod, biped and quadruped—apod, as a fish; biped as a man or a bird; quadruped, as an ox, horse, or other such. Subdivision is the section of the already divided-off branch. For example, the animal is divided into rational and irrational, and then the rational into mortal and immortal. Now, the first thing is divided into two branches: the rational and the irrational. It is the division of one of these branches, namely, the division of the rational into mortal and immortal, that is subdivision. Division and redivision are not used in all cases. However, when everything is not covered by the first division—as, for example, when the animal is divided into rational and irrational, the biped is found both among the rational and the irrational animals—then of necessity we redivide, that is to say, we make a second division of the same thing, and we say: ‘The animal is divided into apod, biped, and quadruped.

For a similar reason, there are eight modes of division. Thus, everything that is divided is divided either according to itself, namely, according to substance, or according to accident. If it is divided according to itself, then it is either as a thing or as a term. If it is divided as a thing, then it is either as genus into species, as when you divide the animal into rational and irrational, or as species into individuals, as man into Peter and Paul and all other individual men, or as a whole into parts. This last division is twofold, being either into like or unlike parts. Now, a thing is of like parts whenever its sections admit of the name and the definition of the whole and of each other. For instance, when flesh is divided into several pieces, each portion is called flesh and admits of the definition of flesh. On the contrary, the thing is of unlike parts whenever the part cut off will not admit either of the name or of the definition, whether of the whole or of the parts. Thus, should you divide Socrates into hands and feet and head, the foot cut off from Socrates would neither be called Socrates nor his head, nor would it admit of the definition either of Socrates or of his head. Or division may be as that of an equivocal term into its various meanings. This, again, is of two kinds, because the term may signify either the whole of something or a part of it. It may signify the whole, as does the word ‘dog,’ since this last is used for land-dog, dog-star, and sea-dog, all of which are wholes and not part of an animal. On the other hand, it may signify a part, as when the name ‘tongue’ is given to the top part of a shoe, to a part of the flute, and to the organ of taste in animals, all of which are parts and not wholes.

The foregoing are the modes in which a thing is divided according to itself. When it is divided according to accident, however, it may be divided as substance into accidents, as when I say that some men are white and some black—for men are substance, while white and black are accidents. Or it may be divided as an accident into substances, as when I speak of animate white things and inanimate white things—for the white is an accident, while the animate and inanimate things are substances. Or it may be divided as an accident into accidents, as when I say that some cold things are white and dry, while others are black and wet—for the cold and the white, the black, and the wet, and the dry are all accidents.

There is still another mode of division, which is that of things which are derivative (ἀφ᾽ ἑνός, from one) and those which are relative (πρὸς ἕν, to one). Things are derivative as in the case of a medical book or a medical instrument deriving from medicine; for from one thing, medicine, medical things are named. On the other hand, a healthful drug or healthful food are relative because they relate to one thing, namely, health. Of the things which are derivative, some derive from some cause—as the man’s image is said to be from the man as from a true cause; whereas others are as having being invented by someone, as the medical scalpel, and the like.

Now, this is the general division according to which everything that is divided is divided. It is either as genus into species, or as species into individuals, or as a whole into parts, or as an equivocal term into its various meanings, or as substance into accidents, or as accident into substances, or as accidents into accidents, or as the derivatives and relatives. There are some who deny the division of species into individuals, because they say that it rather is an enumeration, since all division is into two, or three, or, rarely, into four. But the species is divided into an unlimited number of individuals, because the number of individual men is unlimited.

One must furthermore know that that which is by nature prior and posterior, as well as that which is more and less, is not found to be divided into parts by any mode of division. However, that which is by nature prior and posterior, and that which is more and less, fall under derivatives and relatives—whence their classification.

Chapter 6 (variant)

Division is the first section of the thing. Thus, for example, the animal is divided into rational and irrational. Subdivision is the section and division of one part into two segments. Thus, for example, when the animal has been divided into rational and irrational, then we divide one part—say, the rational—into mortal and immortal. And we have redivision when we have made a division of a thing and then make another kind of division of the same thing over again. Thus, for example, man is divided into male and female—that is division. Then man is divided over again into soul and body—this is redivision. However, division and redivision is not always done, but only when everything is not covered by the first division. It is done in this case, because in both the male and the female body and soul are to be considered.

One should know that the two species into which the same genus is divided are said to be divided by dichotomy. For example, the animal is divided into rational and irrational; so, the rational and irrational are said to be divided by dichotomy.

There are, moreover, eight modes of division: either as genus into species, as the animal is divided into rational and irrational; or as species into individuals, as man is divided into Peter and Paul and all other individual men; or as the whole into parts. This last is of two kinds, for the parts are either alike or they are unlike. They are alike when they admit of the name and the definition of the whole and of one another, as when we cut up pieces of flesh into several pieces of flesh, for then each piece of the flesh is called flesh and admits of the definition of flesh. But they are unlike when they do not admit of the name or of the definition either of the whole or of each other, as when we divide Socrates into hands and head and feet. In this case neither the head, nor the hands, nor the feet admit of the name or of the definition of Socrates, nor do they of each other. Or division is that of an equivocal term divided into its various meanings. This is of two kinds, being either as a whole or as a part. It is as a whole as in the case of the term ‘dog,’ for this is used for a land-dog, and a dog-star, and a sea-dog, which precisely are wholes and not parts of an animal. It is, however, as a part, when the word ‘tongue’ is used for the top part of the shoe, for the endpiece of the flute, and for the organ of taste in animals—which are all some sort of parts and not wholes. Or, again, division is that of substance into accidents, as when I speak of some men being white and some black. Or it is as that of accidents into substances, as when I speak of some white things being animate and others inanimate. Or it is as that of accident into accidents, as when I speak of some cold things being dry and others wet. Or it is as the division of those things which are derivative and relative. We have derivative in the case of a medical book and a medical instrument, which derive from medicine; whereas we have relative in the case of a healthful drug and healthful food, for these relate to one thing, namely health. Now, according to this mode the being is divided into substance and accident.

One must know that that which is by nature prior and posterior and that which is more and less is not divided into parts by any mode of division except that of those things which are derivative and relative.

On That Which Is by Nature Prior

That is by nature prior which is implied in something else, while in itself it does not imply this; and which takes something else away when it itself is taken away, but is not necessarily taken away when the other is. For example, animal is by nature prior to man, for when the animal is taken away so as not to exist, then man will necessarily not exist either, because man is an animal. But, when man is taken away and does not exist, there can still be an animal—for there would be the horse and the dog and such, which are certain kinds of animals. Again, when man is postulated, then animal is most certainly implied with him, because man is an animal. But, when the animal is postulated, man is not necessarily implied, because, on the contrary, it might be a horse, or a dog, or something of the sort, for these are animals, too. Therefore, Peter is not by nature prior to Paul, nor is the rational animal prior to the irrational. For, when Peter is taken away so as not to exist, there will still be Paul. Likewise, when Paul is postulated, Peter is not implied with him; nor, when Peter is postulated, will Paul be implied. And neither is Peter more, that is to say, more a man or more an animal than Paul, nor is Paul more so than Peter. However, a drug may be found which is more healthful than another drug, and a book which is more medical than some other book.

On Definition

A definition²⁴ is a concise statement setting forth the nature of the thing in question, that is to say, such statement as expresses in brief the nature of the thing in question. For example, man is a rational mortal animal capable of intelligence and knowledge. Now, many men have discoursed at length on the nature of man, that is, they have written long and extensive treatises on the subject. But these are not concise and, therefore, are not definitions. There are also concise statements, such as apophthegms, but, since they do not set forth the nature of a thing, they are not definitions. A name, too, oftentimes indicates the nature of the thing in question, but it is not a definition. For the name is one word, while the definition is a statement, and a statement is made up of at least two words. (Therefore, the definition is a name explained, whereas a name is a term of a proposition, when it is in conjunction.)

The definition is made up of genus and constituent, that is to say, essential differences. Thus it is with the definition of animal, for animal is an animate sentient substance. Here the genus is substance, while the constituent differences are the being animate and sentient. The definition may also be taken from matter and form, as, for example: A statue is that which is made of bronze and represents the form of a man. In this case the bronze is the matter, while the representation of the shape of the man is the form of the statue. The matter corresponds to the genus and the form to the specific difference. The definition may also be taken from subject and purpose. Medicine, for example, is concerned with human bodies and is productive of health. Here the subject of medicine is the human body, whereas its purpose is health.

Now, the description is made up of non-essential elements, that is to say, of properties and accidents. For example, man is an animal which is able to laugh, walks erect, and has broad nails. These elements are non-essential. For this reason it is called description, since it outlines, bringing out not the essential substance but only the things consequential to it. The descriptive definition is a combination of essentials and non-essentials, as, for example: Man is rational animal walking erect and having broad nails.

Definition is the term for the setting of land boundaries taken in a metaphorical sense. For, just as the boundary separates that which belongs to one from that which belongs to another, so does the definition set off the nature of one thing from that of any other.

Now, the soundness of a definition lies in its having neither too few nor too many terms, while its vice lies in its having either too few or too many terms. A perfect definition is one which is convertible with the thing defined, while an imperfect one is one which is not. Neither is that which has too few terms convertible (nor that which has too many²⁵), for, when it has too many terms, it covers too few things, whereas, when it has too few terms, it covers too many things. (And so one may say that nature has discovered a wonderful device—poverty that is wealthy and wealth feigning poverty.)²⁶ For example, the perfect definition of man is: Man is rational mortal animal. Notice how this is convertible, for every rational mortal animal is a man and every man is a rational mortal animal. Now, if one term were to be left out, the definition would cover too many things. Take it, for example, as ‘rational animal.’ Here there are too few terms, because I did not say ‘mortal.’ And it covers too many things, because man is not the only rational animal; the angel is one, too. Therefore, it is not convertible. If, on the other hand, I should say ‘a rational, mortal, literate animal,’ again it is not convertible. For by my saying ‘literate’ it has received too many terms, while it covers too few things. This is because it has not defined every man, but only those men who are literate. Thus, every rational, mortal, and literate animal is a man, but not every man is a rational, mortal, and literate animal, because not every man is literate.

Therefore, those definitions are perfect which are convertible with the thing defined. Since, however, a property is also convertible with the thing of which it is a property—for, if anything is a man, it will be capable of laughter; and if anything is capable of laughter, it will be a man—then we must make an additional specification and say that perfect definitions are those which are taken from genus and constituent differences, which are neither deficient nor excessive in terms, and which are convertible with the thing defined. In the same way, those are perfect which are taken from the pairs of subject and purpose and of matter and form. Sometimes this is also true of those taken from the subject alone, as when the subject is not subject to any other art—as glass is not subject to any other art than that of the glass-maker. The same is also true of those taken from the purpose alone, in the case that that purpose is not the purpose of any other art—as with the art of shipbuilding. As a result of all this one must know that the perfection of a definition is in its convertibility.

Definition differs from term by the one being more particular and the other more general. For term is more general than definition, because it means the setting of limits. It also means a decree, as when we say that the king ‘decreed.’ It still further means that into which a proposition is resolved, as with God’s help, we shall learn in that which is to follow. It also means definition. Definition, however, means only the concise statement setting forth the nature of the thing in question.

One must know, furthermore, that a definition is given only in the case of the substance and its species, and that we cannot give a definition of an individual or of accidents, but only a description, because of the fact that the definition is made up of genus and constituent differences, while the description is made up of non-essentials.

On Genus

One must know that in the matter of equivocal terms there are three things to be asked: whether the term is equivocal, how many meanings it has, and of which of these it is a question. Now, first of all, it must be explained what an equivocal term is. Terms are equivocal when two or more things have one name, while each one of them has a different meaning, that is to say, takes a different definition. Such is the case with the term genus,²⁷ for genus is of the number of equivocal terms. Thus, first of all, that is called a genus which is from a place of origin or from a progenitor, and both of these in two ways: either proximately or remotely. It is from the place of origin proximately, as when a person from Jerusalem is called a Hierosolymite, but remotely, as with a Palestinian from Palestine. Similarly, it is from the proximate progenitor, as when Achilles is called Peleides, because he was the son of Peleus; while it is from the more remote, as when Achilles is called Aeacides from his grandfather Aeacus—for the latter was the father of Peleus. Then, again, that relationship is called genus which exists between a person and his several descendants, as when all those descending from Israel are called Israelites. Now, these aforementioned kinds of genus are of no concern to the philosophers.

Again, that is called genus to which the species is subaltern. For example, under animal come man, the horse, and other species; hence, the animal is a genus. It is with this kind of genus that the philosophers are concerned and we define it by saying that genus is that which is predicated in respect to their essence of several things differing in species. Thus, animal, which is a genus, is predicated essentially of man, the horse, the ox, and a number of other things, all of which differ from one another in species. For the species of man is one thing, whereas that of the horse is another, and that of the ox is still another. The genus is predicated as to what something is, for, when we are asked what a man is, we reply that he is an animal. The same is true with the horse, because, when we are asked what it is, we reply that it is an animal. Thus, genus is that to which the species is subaltern. (And again, genus is that which is divided into species.²⁸) For genus is divided into species, is more general than the species, contains the species, and is higher than they.

Now, one should know that the more general is said to be superior, while the more particular is said to be inferior and is subject to predication. Thus, there are things which are subject with respect to existence. Such is substance, because it is subject with respect to the existence of the accident, since the accident subsists in it. There is also that which is subject with respect to predication, and this is the particular. For the genus is predicated of the species as the species is of the individuals. It is clear, however, that the genus is more general than the species, as the species is more general than the individual. In what follows we shall with the help of God learn more accurately about these things. But, now that we have discussed genus, let us also discuss species.

On Species

Species²⁹ is also an equivocal term, since it is used in two different senses. Thus the form and appearance of anything is its species, as, for example, the species of the statue, in which sense it was once said: ‘a first species worthy of sovereignty.’³⁰ There is another kind of species, which is substantial and subaltern to genus. And again, species is that of which genus is predicated in the category of substance. Still again, species is that which is predicated in respect to their common essence of several things which are numerically different. The first two of these descriptions differ only relatively, like ‘ascent’ and ‘descent,’ and they apply to every species. The third and last description, however, applies only to the most specific species,’³¹ which is that which is immediately above the individual and contains the individual substances—as we speak of the human species.

We have related how the term genus is used in three ways—genus from the progenitor and from the place of origin, each in two ways, and genus in a third way, in which the species is subaltern to it. The term species is used in two ways. In one way it is used for the form of anything. In the other way the genus is predicated of it and it is subaltern to genus, as being divided off from it. With this kind of genus and species the philosophers are concerned.

When we were discussing genus, we mentioned species, when we said that genus was that which was divided into species. And again, when discussing species, we mentioned genus by saying that species was that which was divided off from genus. Thus, one should know that when we speak of a father we must needs think of the son, too (for he is a father who has a son), and when we discuss a son we must needs think of the father, too (for he is a son who has a father). And similarly, in this case, it is impossible to discuss genus without species or species without genus, for genus is definitely divided into species and that which does not have species divided off from it is not genus. In the same way, the species are divided off from a genus and those things which do not have a genus are not species.

Now, just as the first man—namely, Adam—is not called a son, because he had no father, but is called a father because he did have sons; and as Seth is both called the son of him who begot him, because he did have Adam for his father, and is also called the father of the one begotten by him, because he did beget Henoch; and as Abel is called a son, because he had Adam for father, but is not called a father, because he had no son—just as with these, so also it is with genus and species. The first genus, since it is divided off from no other genus and has no genus higher than itself, is genus only and not species. This is called the most general genus and we define it by saying that a most general genus is that which, while it is a genus, is not a species, because it has no genus higher than itself. Those things which are divided off from this, if they have other species inferior to themselves and divided from them, are at once species of those prior to them—that is to say, superior to themselves—from which they themselves have been divided off, and genera of those things divided off from them, which is to say, of those inferior to themselves. These are called subaltern genera and species. But the species which are the last and the lowest and which do not possess any lower species, that is, do not contain any species but just individuals—that is to say, individual substances—these are not called genera but just species, because of their not having, as I have said, any lower species divided off from themselves. For it is impossible to call that a genus which neither contains any species nor has any lower species divided off from it. Therefore, that which does not contain any species, but only individual substances, is a most specific species, because, although it is a species, it nevertheless is not a genus. Similarly, the genus which is not a species is called a most general genus.

One should know furthermore that the species necessarily admit of both the name and the definition of their genus, and the genera of their genera up as far as the most general genus. The species, however, cannot admit of each others’ definition. Now, to make the matter under discussion clearer, let us look at it in the following manner. Substance is the first and most general genus, for, although substance as well as accident is divided from being, being is not their genus. This is because, although they both admit of the name of being, they do not admit of its definition. A being is a thing which is either self-subsistent and without need of any other for its existence or which cannot exist of itself but has its existence in another. But, substance is a self-subsistent thing and has no need of another for its existence, and that is all. Thus, substance does not admit of the entire definition of being. Consequently, being is not the genus of substance, nor is substance [a species] of being, for the species admits of the definition of its genus in its entirety. What is more, accident is not a species of being either—because it does not admit of its entire definition, but only of half of it. This is because an accident is a thing which cannot exist of itself, but only has its existence in another. Thus, neither substance nor accident admit of the entire definition of being, but substance admits of one half and accident of the other. And so, even though being is divided into substance and accident, it is not their genus. Substance, however, is divided into corporeal and incorporeal substance. Here, the corporeal and the incorporeal are species of substance, because each of them admits of the name and the definition of substance. Thus, substance is not a species, because it has no genus higher than itself; rather, it is a first and most general genus. And again, the corporeal substance is divided into animate and inanimate. Here again, while the corporeal substance is a species of substance, it is the genus of the animate and inanimate. The animate is further divided into sentient and non-sentient. Now, the animal is sentient, because it has life and sensation; whereas the plant is non-sentient, because it does not have sensation. The plant, however, is called animate because it has faculties of assimilating food, of growing, and of reproducing. Again, the animal is divided into rational and irrational. The rational is divided into mortal and immortal, and the mortal into man, the horse, the ox, and the like, which admit no further division into other species, but only into individuals, that is to say, into individual substances. Thus, man is divided into Peter, Paul, John, and all other individual men, who are not species but hypostases. For the species, as we have said, do not admit of each other’s definition. For example, the corporeal substance does not admit of the definition of the incorporeal, nor does man admit of the definition of the horse. Peter and Paul and John, however, do admit of one definition: that of man. It is the same for all other individual men; hence there are not various species of men, but individuals, that is to say, hypostases.

Again, when the species is divided, it communicates both its name and its definition to those inferior to itself. However, when Peter is divided into body and soul, he does not communicate his name and his definitions either to the soul or to the body. For Peter is not the soul alone or the body alone but both of them together.

Still further, every division of genus into species will go as far as two or three or, very rarely, four species, because it is impossible for a genus to be divided into five or more species. Man, on the other hand, is divided into all individual men, and these are unlimited in number. For this reason there are some who say that that which is from species to individuals is not to be called division, but enumeration. Whence it is clear that Peter and Paul and John are not species but individuals, that is to say, hypostases. Nor is man the genus of Peter and Paul and John and the other individual men, but their species. Thus, man, too, is a most specific species, for he is a species belonging to the superior order in so far as he is contained under it; and he is the species of those inferior to himself, in so far as containing them. For, that which is contained by a genus is a species, and that which contains the individuals, or individual substances, is also species. This last, then, is the most specific species, which comes immediately above the individuals, and which they define by saying that it is a species which is predicated in the category of essence of several numerically different things. In the same way, the horse and the dog and other such species are most specific. Those which stand between the most general genus and the most specific species are subaltern genera and species—species of the superior order and genera of the inferior.

Then there are also the essential and natural differences and qualities which are called dividing and constituent, because they divide the superior and constitute the inferior. Thus, the corporeal and incorporeal divide substance. Similarly, the animate and the inanimate divide the body. Similarly, the sentient and the non-sentient divide the animate. These, then, go to make up the animal, for I take an animate sentient substance and I have an animal, because the animal is an animate sentient substance. Again, I take an inanimate non-sentient substance and I have a stone. Again, I take an animate non-sentient substance and I have a plant. Further still, the rational and the irrational divide the animal, and the mortal and the immortal divide the rational. So I take the animal, which is the genus of these last, and the rational and the mortal and I have a man, for man is a mortal rational animal. Then I take the animal and the irrational and the mortal and the terrestrial and I have a horse, a dog, and the like. Or I take the irrational and the mortal and the aquatic and I have a fish. Now, differences are called essential and natural, because they make one species differ from another and one nature and essence from another essence and nature.

Chapters 9-10 (variants)

The term genus is used in three senses: in one sense, as coming from the progenitor, as those descended from Israel are called Israelites; in the second sense, as coming from the place of origin, as those from Jerusalem are called Hierosolymites and those from Palestine Palestinians; and, in the third sense, that is called genus which is divided into species. With this last the philosophers are concerned, and they define it by saying that genus is that which is predicated in respect to their common essence of several things which are specifically different.

The term species has two meanings. Thus, appearance and form are called species, as for example, the species of the statue. That is also called species which is subordinate to genus, that is to say, divided off from a genus. With this last the philosophers are concerned.

Now, when we are discussing genus, we mentioned species by saying that genus was that which was divided into species. Again, when discussing species, we mentioned genus by saying that species was that which was divided off from genus. One should know that when we discuss the father we must needs think of the son, too (for he is a father who has a son), and when we discuss the son we must needs think of a father, too (for he is a son who has a father). And similarly in this case it is impossible to treat of the genus without the species, or the species without the genus, for the genus is definitely divided into the species and that which does not have species divided off from itself is not genus. In the same way, the species are divided off from the genus and those things which do not have a genus are not species. And just as the first man—that is to say, Adam—is not called a son, because he had no father, but is called a father because he did have sons; and just as Seth is called both son of him that begot him, for he had Adam for his father, and father of him begotten by him, for he did beget a son; and just as Abel is called a son, because he had Adam for his father, but is not called a father, because he had no son— so also is it with genus and species.

The first genus, which is not divided off from a genus and has no higher genus, is genus only and not a species. This is called a most general genus and they define it by saying that a most general genus is that which, while it is a genus, is not a species with a genus higher than itself. Those things which are divided off from this, if they have other species lower than themselves and divided off from themselves, are at once species of those before them—that is to say, higher than themselves—from which they are divided off, and genera of those divided off from themselves—that is to say, of those which are lower than they. These are called subaltern genera and species. However, the species which are the last and the lowest and which do not have any lower species are not called genera but only species, because they have no lower species divided off from them. For it is impossible to call that a genus which neither contains any species nor has any lower species divided off from itself. Therefore, the species which has no species is called a most specific species.

One should know that the species must admit of the name and definition of their genus and that the genus must admit of those of its genus up as far as the most general genus. The species, however, cannot admit of each other’s definition. Substance is a first and most general genus. For, even though substance and accident are divided from being, being is not their genus; and, although they do admit of the name of being, they do not admit of the definition. Being is defined as that which is either self-subsistent and without need of any other for its existence, or that which cannot exist of itself but has its existence in another. Now, substance is a thing which is self-subsistent and without need of another for its existence, and it is that alone; accident is a thing which cannot exist in itself, but has its existence in another, and it is that alone. Thus, neither substance nor accident admits of the entire definition of being, but substance admits of one half and accident of the other. Species, however, will admit of both the name and the entire perfect definition of their genus. And so, even though being is divided into substance and accident, it is still not their genus. Nor, indeed, is substance a species with a genus higher than itself. On the contrary, it is a first and most general genus.

This substance, then, is divided into corporeal and incorporeal. Hence, the corporeal and the incorporeal are species of substance. Again, corporeal substance is divided into animate and inanimate. Here again the corporeal, while it is a species of substance, is the genus of the animate and the inanimate. Again, the animate is divided into sentient and non-sentient. Now the sentient is the animal, because it has both life and sensation; but the non-sentient is the plant, because it does not have sensation. The plant is called animate because it has the faculties of assimilating food, of growth, and of reproduction. Again, the animal is divided into rational and irrational. The rational is divided into mortal and immortal. The mortal is divided into rational man and the irrational animals such as the horse, the dog, and the like. None of these last is divided into any further species; they are divided into individuals, that is to say, individual substances. Thus, man is divided into Peter and Paul and John and all other individual men, who are not species, because species, as we have said, do not admit of each other’s definition. For example, the corporeal substance does not admit of the definition of the incorporeal. Man does not admit of the definition of the horse. But Peter and Paul and John do admit of one definition—that of man. And it is the same way with all other individual men. So, these last are not species of man. but they are individuals, that is to say, hypostases.

Again when the species is divided, it communicates both its name and its definition to those lower than itself. On the contrary, when Peter is divided into body and soul, he communicates neither his name nor his definition to the soul or the body. (For neither is the soul alone Peter, nor is the body; rather, he is both together.³²)

Still further, every division of genus into species will go as for as two or three, but very rarely to four species, because it is impossible for a genus to be divided into five or more species. But man is divided into all individual men, who are unlimited in number. For this reason there are some who say that that which is from species to individuals is not to be called division, but enumeration. Whence it is clear that Peter and Paul and John are not species but individuals, that is to say, hypostases. Neither is man the genus of Peter and all of the other individual men, but their species. For this reason man is a most specific species, because he is a species in relation to the higher and species in relation to the lower. Similarly, the horse, the dog, and the like are species and not genera, for which reason they are most specific species. Those coming in between the most general genus and the most specific species are subaltern genera. They are species of the higher and genera of the lower.

Then, there are also the essential and natural specific differences and qualities which are called dividing and constituent, because they divide the higher and are constituent of the lower. Thus, the corporeal and incorporeal substances divide substance. Similarly, the animate and inanimate divide the corporeal substance. Similarly, the sentient and non-sentient divide the animate. These, then, go to make up the animal, for I take an animate sentient substance and I have an animal, because the animal is an animate sentient substance. Then, I take an inanimate non-sentient substance and I have a stone. Again, I take an animate non-sentient substance and I have a plant. Then, again, the rational and the irrational divide the animal, and the mortal and the immortal divide the rational. So, I take the animal, which is the genus, and the rational and the mortal and I have a man, for a man is a mortal rational animal. And I take the animal and the irrational and the mortal and I have the horse, say, or the dog, or the like. Now, differences are called essential and natural, because they make one species differ from another and one nature and essence differ from another essence and nature.

On Individual

The term individual³³ is used in four senses. Thus, that which cannot be divided or partitioned is called individual, as the point, the instance of the time which is now, and the unit. These are said to be quantitiless (that is to say, without quantity³⁴). That also is called individual which is hard to divide, that is to say, is difficult to cut up, as is the diamond and the like. That species is also called individual which is not further divisible into other species; in other words, the most specific species, such as man, the horse, and so forth. The term individual, however, is principally used as meaning that which, although it is divisible, does not maintain its species intact after the division. Thus, Peter is divided into soul and body, but neither is the soul by itself a perfect man or a perfect Peter, nor is the body. It is with this latter kind of individual—namely, that which shows the individuality of the substance—that the philosophers are concerned.

On Difference

Difference³⁵ and quality and property are all the same thing in relation to their subject, but in relation to their operation they are different. Thus, rationality is said to be both a quality and a property and a difference of man, but it is these in different ways. Thus, on the one hand, in so far as it makes and, as it were, forms the substance, it is said to be a quality. Then, in so far as it becomes peculiar to this substance, it is said to be a property. But, in comparison with the irrational—an ox, say, or a mule, or a dog—then it is said to be a difference, because in it man differs from the irrational animals.

The term difference is used in three senses: in a common sense, in a special sense, and in a very special sense. For it is impossible to find any two things which do not differ from each other in something. Thus, in some things species differ from species; in others an individual substance differs from another of the same species and substance; and in others an individual substance differs from itself. For the species of man differs from that of the horse by the rational and the irrational, the rational and the irrational being said to constitute an essential difference. Similarly, all things by which species differs from species are called natural and essential and constituent and specific difference and quality (and a natural property, as inhering unchangeably in the whole species). This is called by the philosophers a very special difference, as being indicative of the nature and more proper to it. Again, a man differs from a man, or a horse from a horse, or a dog from a dog (that is, an individual differs from an individual of the same species), according as one is large and the other small, or as one is old and the other young (or as one is flat-nosed and the other sharp-nosed),³⁶ or as one is intelligent and the other stupid. All these are called non-essential differences and qualities, which is precisely what an accident is, concerning which we shall speak directly.

On Accident

An accident³⁷ is that which may either be present or absent without destroying the subject. Again, it is that which can be or not be in the same thing. Thus, it is possible for a man to be white or not, and also for him to be tall, intelligent, or flat-nosed or not. (For the presence of this does not save the species, because it does not belong to the definition of the species. Neither does its absence destroy the species. Thus, even though the Ethiopian is not white, this in no wise keeps him from being a man. And so, whether it is present or absent, it does not injure the subject substance—for we have said that the substance is a subject and sort of matter for the accidents.³⁸)

The accident is divided into two kinds: that which is commonly called a difference and that which is properly a difference. What is commonly called a difference is the separable accident. For example, one person is seated and another standing. Now, by the standing up of the one who is seated and the sitting down of the one who is standing it is possible for the original difference between the two to be removed and replaced by another difference. And one is also said to differ from oneself by a separable accident, for one does differ from oneself by sitting down and standing, by being young and growing old, by being sick and getting well, and so forth. A difference in the proper sense is the inseparable accident. For example, a person is snub-nosed and it is impossible to separate his snub-nosedness from him, and similarly with his being gray-eyed and the like. Thus, it is by these inseparable accidents that one individual, that is, one individual substance, differs from another. However, one’s own self never differs from oneself. Now, the accidents do not enter into the definition (of the nature³⁹), because it is possible for a man to be snub-nosed or not, and, just because a man does not have gray eyes, he remains no less a man.

On Property

There are four ways in which a thing is said to be property.⁴⁰ In the first place, that is said to be a property which is in one species only but not in the entire species. Such, for example, is the ability which man has for land-surveying, for only man surveys land, yet not every man does have this ability. Secondly, that is said to be a property which belongs to the entire species but not to just one species. An example would be the having of two feet. Thus, every man is a biped, but not man only, because the dove is a biped, too, and so are others of the sort. Thirdly, that is said to be a property which is in the whole species and in it alone but not always. Such is the becoming gray-haired in man, because this is proper to every man and to man alone, yet not always, but only in old age. Fourthly, that is said to be a property which arises from the combination of the first three, namely, that which is in an entire species, is in that species only and always, and is convertible like laughter in man, neighing in the horse, and so on. For only man can laugh and every man can laugh and can always do so, even though he may not always exercise this power. (Thus, if something is a man, it most certainly can laugh; and if something can laugh, it is most certainly a man. And that is what is meant by being convertible. It is with this last meaning that the philosophers are concerned.⁴¹) Now, to describe it we say that a property is that which belongs to a single species, to the whole species and always. This has a threefold division: being from the way a thing is formed, that is to say, the way it is shaped, as is the being broad-nailed and walking erect in man; being from the operation of the thing, as the being carried upward which is proper to fire; or being from the potentiality of the thing, as we say that the fire has a power of heating which exceeds the heat of other bodies. The property, moreover, is said to be added over and above the essence, or adventitious.

On Predicates

Every predicate⁴² is either more extensive than its subject or co-extensive with it, but it is never less extensive. It is more extensive when more general things are predicated of more particular ones. The more general, then, are the superior, whereas the more particular are the inferior. And the most general thing of all is the being, for which reason it is predicable of all things. For, substance is called a being, and so is accident called a being. But we cannot say that the being is substance, because not only is substance being, but so is accident. Genera, likewise, are predicable of their species, because they are more general; but the species are not predicable of their genera, because they are less general than their genera. Thus, substance is predicated of the animal, and the animal is predicated of man. This is because the animal is a substance and man is an animal. This is not, however, convertible, because, although every man is an animal, not every animal is a man—for the horse and the dog are animals, too. Moreover, not every substance is an animal, for stone and wood are substances which are not animals. Similarly, the species is predicable of the individuals contained in it, that is to say, of the individual substances, because the species is more general. But the individual, that is to say, the individual substance, is not predicable of the species, because the individual substance is more particular than its species. Thus, Peter is a man and Paul is a man, but not every man is Peter or Paul, because there are other persons contained in the human species. The differences also are predicable of the species in which they inhere and of their individuals. This is because the differences are more general than the species. Thus, the rational is more general than the species of man, because, although every man is rational, not every rational being is a man. Although the angel also is rational, he is not a man. Such, then, is the predicate which is more extensive.

The predicate, on the other hand, is co-extensive with its subject, when it is convertible. Thus, properties are predicated of the species of which they are properties; and the species are predicated of their properties. For every man is capable of laughter and everything that is capable of laughter is a man. Even though a monkey may also be said to laugh, it does not laugh with its heart but only with its features, because it is an animal which is good at mimicking. And so, the predication of the genera of their species, that of the differences of their species and that of the species of their individuals, are said to be more extensive; while that of the properties is said to be co-extensive. Those which are co-extensive are convertible and are called reciprocal predicables.

On Univocal and Equivocal Predication

Predication is univocal when the subject admits of both the name and the definition of the name itself. For instance, the animal is predicated of man and admits of both the name and the definition of the animal, because an animal is an animate sentient substance and man admits of this definition. For man is an animate and sentient substance.

On the other hand, predication is equivocal when the subject admits indeed of the name, but not at all of the definition. For instance, the picture of a man admits of the name of the man, but it does not admit of the definition of man. For man is defined as a rational animal which is mortal and which is capable of understanding and knowing. The picture, however, is neither an animal (for it is not animate), nor is it rational or capable of understanding and knowing.

One should know that whatever is predicated of something as of a subject, predicated univocally, that is, will also be predicated of that which comes under it. For example, the animal is predicated of man as of a subject, that is to say, univocally. Man, in turn, is predicated of Peter, for Peter comes under man. Therefore, the animal is also predicated of Peter, because Peter is also an animal.

The term subject is taken in two ways: as subject of existence and as subject of predication. We have a subject of existence in such a case as that of substance, which is the subject of accidents, since these have existence in the substance, which is the subject of accidents, since these have existence in the substance but outside of it do not subsist. On the other hand, the subject of predication is the particular, for with predication the particular is subject to the more general, since the more general is predicated of the more particular—as the animal is predicated of man. Now, that which is universal is affirmed of a subject whereas that which is more particular is a subject of predication. And the accident is said to be in the substance as in a subject, whereas the substance is said to be a subject of existence.

On the Predication of the Essence of a Thing and on That of Its Sort

Predication of the essence of a thing is one thing, whereas that of its sort is another. Predication is of the essence of a thing when, being asked what a man is, we reply: ‘an animal.’ But it is of its sort when, being asked what sort of an animal, we answer: ‘a rational mortal animal.’ Thus, the genus and the species are predicated of the essence of a thing; whereas the difference, whether essential—that is to say, whether property or accident—is predicated of its sort. The individual substance neither signifies what the thing is nor of what sort it is, but it does signify which one it is. Thus, when we are asked who this man is, we reply that he is Peter. Then, when asked what sort of man he is, we reply that he is tall, let us say, or short.

Moreover, one should know that things which differ in nature are said to be one thing and another. Thus, we say that man is one thing and the horse another, and we mean another thing in nature, because the species of man is one thing and that of the horse is something else. Those things, however, which differ in number, that is to say, which are individual substances, are said to be one and another. Thus, we say that Peter is one and Paul another. However, we cannot say that Peter is one and Paul another, because, if we did, we should not be telling the truth. For in nature they are one thing, but numerically they are not.

And one should know that the substance is called another thing, and likewise the essential differences, while the accident is called something of another sort. This is because the essential differences are considered in connection with the species, that is to say, in connection with the nature which they go to make up. The accident is considered in connection with the individual, because the accidents are constituent of the individual substance. A man, then, is one thing and a horse another, but Peter is of one sort and one and Paul of another sort and another. Moreover, every difference, whether essential or not, makes for something else of a different sort (ἑτεροῖον), for ἑτεροῖον means both something else and a thing of a different sort. The nature, then, signifies what a thing is, whereas the individual substance specifies this certain person or thing and every difference shows of what sort something is.

What the Five Terms Have in Common and in What They Differ

One must know that the five terms have this in common with each other, that they are all predicated of several things.⁴³ But they differ from one another for the following reason, namely, that: while genus is predicated of the essence of several things differing in species; species is predicated of the sort of several things differing in number; difference and accident are predicated of the sort of several things differing in species; and property is predicated of the sort of several things differing in number, that is, of one species and the individuals contained in it. Moreover, the difference differs from the accident in that, while the difference is essential, that is to say, is a part of the substance of the subject, the accident does not exist as a part of the substance but as a non-essential.

What Genus and Difference Have in Common and in What They Differ

Genus and difference⁴⁴ have this in common, that they both contain the species and that they are both predicated univocally of species and individuals. One should furthermore know that whatever is predicated of something as of a subject, that is, univocally, will also be predicated univocally of what comes under this. In the case of equivocal predication, however, that will by no means be true. The distinguishing peculiarities of the genus as compared with the difference are: that the genus is more extensive than the differences under it and than the three other terms; that the genus contains the differences virtually; that the genus is prior by nature to the differences; that the genus is predicated of the essence of a thing, whereas the difference is predicated of its sort; that the related genus is one, whereas the differences are several; and that the genus corresponds to matter, whereas the difference corresponds to form.

What Genus and Species Have in Common and in What They Differ

Genus and species⁴⁵ have this in common: that they are predicated of the essence of several things; that by nature they are prior to those things that come under them; and that each is a whole something. Distinguishing peculiarities of genus and species are as follow, namely: that the genus is more general than the species; that the species is richer in differences than the genus; that the genus is predicated of the species univocally, whereas the species is not convertible; and that neither is the genus more specific, nor the species most general, nor can that which is most specific be a genus.

What Genus and Property Have in Common and in What They Differ

Genus and property⁴⁶ have this in common, namely: that they both follow the species, that is to say, are predicated of them; that they are both predicated equally of the things of which they are predicated; and that they are predicated univocally. The differences between genus and property are: that the genus is prior by nature to the property; that the genus is predicated of several species, whereas the property is predicated of one; that the property is convertible with the species, but the genus never; and that the property exists in just one species, while the genus does not.

What Genus and Accident Have in Common and in What They Differ

Genus and accident⁴⁷ have this in common: that they are predicated of several things. Distinguishing peculiarities of genus and accident are: that the genus is prior to the species in which the accidents subsist, whereas the accidents are posterior to the species; that the participation of the genus is equal, but not that of the accidents; that the accident exists antecedently in the individuals and consequently in the species, whereas the contrary is true of the genus; and that the genera are predicated of the essence of a thing, whereas the accidents are predicated of its sort, or how the thing is.

What Difference and Species Have in Common and in What They Differ

Difference and species⁴⁸ have this in common: that they are participated in equally, and that they are always present in the things which participated in them. Distinguishing peculiarities of difference and species are these: that the difference is predicated of what sort something is, and the species of its difference; that the difference contains several species and their individuals, whereas the species contains only the individuals which come under itself; that the difference is prior by nature to the species; and that a difference may be combined with a difference, but a species with a species never.

What Difference and Property Have in Common and in What They Differ

Difference and property⁴⁹ have this in common: that they are predicated equally of all the things that participate in them, and that they are always present in the whole species. Distinguishing peculiarities of difference and property are: that, whereas the difference contains several species, the property contains only one; and that the difference is not convertible with the species, whereas the property is.

What Difference and Accident Have in Common and in What They Differ

Difference and accident⁵⁰ have this in common: that they are both predicated of several things as to what sort they are, and that the difference and the inseparable accident are always present in the things of which they are predicated. One of the distinguishing peculiarities of difference and accident is that the differences contain and are not contained, while the accidents are contained. For, on the one hand, both contain the species, as being predicated of several species; but the difference is not contained, because the same species does not admit of contradictory differences. On the other hand, the accident is contained, for the reason that the same species and the same individual will admit of several accidents which may oftentimes even be contradictory. Other distinguishing peculiarities are: that the difference does not admit of more or less, whereas the accidents on the contrary do, and that contradictory differences may not be combined, whereas contradictory accidents may.

What Species and Property Have in Common and in What They Differ

Species and property⁵¹ have this in common: that they are mutually predicable of each other, that is to say, that they are convertible; and that they are participated in equally because they do not communicate themselves to any one of the individuals participating in them more or less than to any other. Differences between species and property are: that the species is essential, whereas the property is super-added to the essence; that the species is always in act, whereas the property is always in potency and not always in act; and that those things which have different definitions are manifestly themselves different also.

What Species and Accident Have in Common and in What They Differ

Species and accident⁵² have this in common: that they are predicated of several things. Differences between species and accident are: that the species is predicated of the essence of a thing, whereas the accident is predicated of its sort; that one may participate in just one species, whereas anyone may participate even in several accidents; that the species is by nature prior to the accidents; and that participation in the species is equal, whereas the accidents admit of more or less.

What Property and Inseparable Accident Have in Common and in What They Differ

Property and inseparable accident⁵³ have this in common: that without them those things in which they inhere cannot exist, and that both are always present. Distinguishing peculiarities of property and accident are: that the property belongs to one species, whereas the accident belongs to several; that whereas the property is convertible with the species, the accident never is; and that, whereas the accident admits of more or less, the property by no means does.

On Hypostasis, Enhypostaton, and Anhypostaton

The word hypostasis has two meanings. Thus, when used in the strict sense it means substance simply. However, the hypostasis subsisting in itself means the individual and the distinct person. Enhypostaton, or what has real existence, has two meanings also. Thus, it may mean being in the strict sense. In this sense we not only call substance in the strict sense enhypostatic but the accident, also. And it also means the hypostasis in itself, that is to say, the individual. Anhypostaton, or what has not real existence, is also used in two senses. Thus, that which has absolutely no existence at all is called anhypostaton, and the accident is also so called, because it does not subsist in itself but in the substance.

On Substance, Nature, and Form; as Well as on Individual, Person, and Hypostasis

In this same way the pagan philosophers stated the difference between οὐσία, or substance, and φύσις, or nature, by saying that substance was being in the strict sense, whereas nature was substance which had been made specific by essential differences so as to have, in addition to being in the strict sense, being in such a way, whether rational or irrational, mortal or immortal. In other words, we may say that, according to them, nature is that unchangeable and immutable principle and cause and virtue which has been implanted by the Creator in each species for its activity—in the angels, for thinking and for communicating their thoughts to one another without the medium of speech; in men, for thinking, reasoning, and for communicating their innermost thoughts to one another through the medium of speech; in the brute beasts, for the vital, the sentient, and the respiratory operations; in the plants, for the power of assimilating nourishment, of growing, and reproducing; in the stones, the capacity for being heated or cooled and for being moved from place to place by another, that is to say, the inanimate capacity. This they called nature, or the most specific species—as, for example, angel, man, horse, dog, ox, and the like. For these are more general than the individual substances and contain them, and in each one of the individual substances contained by them they exist complete and in the same manner. And so, the more particular they called hypostasis, and the more general, which contained the hypostases, they called nature, but existence in the strict sense they called οὐσία, or substance.

The holy Fathers paid no attention to the many inane controversies, and that which is common to and affirmed of several things, that is to say, the most specific species, they called substance, and nature, and form—as, for example, angel, man, horse, dog, and the like. For, indeed, οὐσία, or substance, is so called from its εἶναι, or being; and φύσις, or nature, is so called from its πεφυκέναι, or being. But εἶναι and πεφυκέναι both mean the same thing. Form, also, and species mean the same thing as nature. However, the particular they called individual, and person, and hypostasis or individual substance—as, for example, would be Peter and Paul. Now, the hypostasis must have substance together with accidents, and it must subsist in itself and be found to be sensibly, that is, actually, existent. It is furthermore impossible for two hypostases not to differ from each other in their accidents and still to differ from each other numerically. And one should know that the characteristic properties are the accidents which distinguish the hypostasis.

On Equivocals

Those things are equivocal⁵⁴ which have a common name, but which differ in their definition or description. The term dog, for example, is an equivocal one, because it means both the land-dog and the sea-dog. The land-dog, however, has one definition, while the sea-dog has another, because one is one nature and the other is another. Now, equivocals are described as follows: those things are equivocal which have only their name in common, while the statement of the substances signified by the name is diverse. Take ‘statement’ here as meaning definition or description; and take ‘by the name’ as showing that the definitions of the name are diverse, for which reason the things are equivocal. Take, for example, the land-dog and the sea-dog. These are equivocal because of their name—dog. For, should anyone wish to give the definition of the land-dog and of the sea-dog, he will, in so far as each one of them is called a dog, give one definition of dog to the land one and another to the sea one. Nevertheless, it is possible for these to have a common definition as well as a common name. Thus, both are called animals and admit of the definition of the animal. In the name of animal, however, they are not equivocal, but univocal. Moreover, in the case of equivocal things one must ask three questions, namely: whether it is equivocal, in how many senses it is taken, and which meaning is in question.⁵⁵

Although the ancients were of the opinion that likeness arose in four ways from quality alone, the more recent have thought that primarily and summarily it arises both from substance and quality. There is likeness in substance, as when we say that men are like angels, implying that they are equal to them, even though in their qualities men and angels do differ from each other very much. And in the same way we speak of horses, swans, and the like. However, since this likeness sometimes appears as without variance and sometimes with some variance, the heretics who made the Son to be inferior would say that He was like the Father, and thus by the ambiguity of the term they would lead astray more simple folk. It is for this very reason that Basil the Great says: ‘If the “without variance” be added, then I, too, accept it.’⁵⁶ So much, then, for likeness in substance. Likeness in quality is not just in this quality or that, but in every quality—that is to say, in shape, form, color, skill, virtue, and whatever else is included in the nature of quality.

Now, this likeness⁵⁷ has a fourfold division. Thus, it may be in one species and one quality, as when we say that things of the same species are like each other. For instance, we say that the Ethiopians are like each other in their being black, and again, that swans are alike in their being white. And so, these last are like each other in two ways, both in substance and appearance, that is to say, color. Or likeness may be in different species that have one and the same quality, as, for example, white and black pepper are like each other in quality. Or it will be in the same species with different qualities, as, for example, the pigeon is like the dove in its being white, and purple, and black, and in other things which they may have in common. But the quality of these last is different. A fourth kind of likeness is the appearance which is in the image and its original, as it would be with the picture of an animal and the live animal. In this way, too, they say that we are like God. Nevertheless, anyone who considers the matter carefully will discover how very great a difference there is. For the former have nothing else in common but their name and form, while man has that which is most important in him in common with God, namely, goodness, and wisdom, or even power. Yet, man is not absolutely like God, because God has these things by nature and we have them by adoption—each in a different way. And so, not only is the difference between God and man infinite, but also that between individual men proportionately. Likeness, therefore, is like the relation of things which are derivative and relative.

On Univocals

All those things are univocal⁵⁸ which have in common both their name and the definition or description of their name. For example, the term animal signifies both man and the horse. And in this name, that is, in the name animal, they are univocal, because each of them admits both of the name and of the definition of the animal. Now, they describe univocal things as follows: those things are univocal which have a common name and the same definition for the substance signified by that name.

On Multinominals

All those things are multinominal⁵⁹ which have the same definition but differ in name. In other words, a thing is multinominal when this same thing is called by several names. Such, for example, would be sword, blade, broadsword, rapier, claymore. For all these names admit of one definition, namely, a double-edged piece of steel, that is, a piece of steel sharpened on both edges. Multinominals are described as follows: several names applied to one thing.

On Things Which Are Different and on Heteronymous Things

Those things which differ in both, that is to say, in name and definition, may have one subject.⁶⁰ In such a case they are called heteronymous, as are ascent and descent, for they have one subject—the incline. Or they may not have one subject; in which case, they are called different. Such are substance and accident, because they both have different names and different descriptions and they do not have one subject. The description of both of these, the heteronymous and the different, is this: Those things of which the name and the definition are diverse.

On Conjugates

Midway between the equivocals and the univocals there are certain other things which both share and differ in their name and definition and which are called conjugates.⁶¹ Such is ‘grammarian,’ which is derived from ‘grammar.’ These do share in their name, but they differ in the ending of the name, that is, in the last syllables. Furthermore, they both share and differ in their definition, because grammar is a knowledge, whereas the grammarian is the substance in which that knowledge is. Those things, then, are conjugates which get their appellation from something by inflective variation, that is to say, variation of the name of the thing.

Moreover, one must know that grammar and music and justice are not derivatives, but that the musician, the grammarian, and the just are. This is because grammarian is derived from grammar, musician from music, and just from justice.

And one must know that the conjugates contain the things from which they are derived, as the grammarian contains the grammar and the just man justice. This, however, is by no means true in the case of things which are derivative. Thus, the medical instrument does not contain medicine.

On the Ten Most General Genera

Some things which are affirmed are affirmed simply and without combination, as are substance, accident, and the like. Others, however, are affirmed in combination, as ‘a horse runs’ or ‘Socrates philosophizes.’ Of those things which are affirmed simply and without combination, one signifies substance, as, for example, man or horse; another, quantity, as, for example, two or three, two cubits long or three cubits long; another, relation, such as father or son; another, quality, such as white or black; another, place, such as in a temple or ina marketplace; another, time, such as last year, yesterday, or today; another, position, such as standing or sitting; another, state, such as being dressed or being shod; another, action, such as burning or cutting; another, passion, such as being burnt or being cut. In so far as these ten are affirmed of certain things, they are called categories, because to categorize is the same thing as to affirm.⁶²

One should know, moreover, that each of the ten categories is a most general genus. Now, of these ten categories, which are also most general genera, one is substance, whereas the other nine are accidents. The ten are: (1) substance, (2) quantity, (3) relation, (4) quality, (5) time, (6) place, (7) position, (8) state, (9) action, and (10) passion.

On Things Which are Generically the Same and Specifically the Same; and on Things Which Are Generically Different, Specifically Different and Numerically Different

All things that fall in the same category are generically the same (as man and horse).⁶³ Generically different are all those that fall in different categories (as animal and knowledge). They are different in genus. On the other hand, all things that come under the same species and thus have their substance in common, as Peter and Paul, are specifically the same. But those are specifically different which differ from one another in species, that is to say, by reason of their substance, as do man and the horse. All those things are numerically different which by the combination of their accidents have marked off for themselves the individuality of their own individual substance and have thus acquired individual existence, that is to say, those that are individuals, such as Peter and Paul and all other individual men.

The differences of all things that are generically different are also specifically different, as, for example, those of animal and knowledge—for the animal comes under substance, whereas knowledge comes under quality. Constituent differences of the animal are the animate and the sentient, whereas the rational, the irrational, the winged, the terrestrial, or the aquatic are dividing differences. On the other hand, constituent differences of knowledge are its inherence in animate rational beings and, besides this, its tendency to inalterability; whereas grammar and philosophy are dividing differences. For to that category to which the genus belongs the species also belongs, and so also do the differences of the species. And nothing prevents the same differences from belonging to the subaltern genera and species, but not all, because, for example, the living cannot make the non-living. Now, by differences here I mean those which constitute the genera and the species.

Moreover, one should know that the nine categories which are not substance, even though they are accidents, do each one have constituent and dividing differences. Each is a most general genus and each has subaltern species and genera and most specific species. For, without exception, where there is a genus, there there are species and dividing differences, since they are what divide the genera into species. And where there are species, there there are differences also, for they are what constitute the species.

The term ‘one’ is used in three ways. Either it will be one in genus, as, for example, we say that man and the horse are generically one and the same, because they belong to one genus, namely, the animal. Or it will be one in species, as we say that, since Socrates and Plato belong to one species, man, they are specifically one and the same. Or it will be one in number, as we say that Socrates is in himself one, being distinct from all other men.

On Being in Something

There are eleven ways of being in something:⁶⁴ (1) as genus in species, as the animal is in the definition of man; (2) as species in genus, as man is in the division of the animal; (3) in a place, as a priest in the temple; (4) in time, as Noe in the time of the flood; (4) in a receptacle, as wine is in a jar; (6) as a whole in parts, as Socrates in his own members, in his head, hands, and feet—although this is not being in something but, rather, in some things; (7) as the part in a whole, as the head or hand in Socrates; (8) as form in matter, as the form of the statue in the bronze; (9) as in the efficient cause, as all things are in God; (10) as in the final cause, as the bed is in man’s rest, because it is for the purpose of man’s resting that the bed is made; (11) as in a subject, as whiteness is in a body. One should know, moreover, that parts are said to belong to a whole, but a whole is never said to belong to parts but rather to be a whole in parts.

Again on Substance

Substance is a thing which subsists in itself and has no need of another for its existence. And again: substance is everything that subsists in itself and does not have its existence in another—that is to say, that which is not because of any other thing, nor has its existence in another, nor has need of another to subsist, but which is in itself and is that in which the accident has its existence. Thus, color was made because of the body, that it might color it, but the body was not made because of the color. And the color exists in the body, not the body in color. For this reason the color is said to belong to the body and the body not to belong to the color. Thus, for example, although the color may often be changed and altered, yet the substance, that is to say, the body, is not changed but remains the same. Now οὐσία, or substance, is so called from its εἶναι, or being (in the proper sense. On the other hand, συμβεβηκός, or accident, is so called from its συμβαίνειν, or happening, and sometimes being and sometimes not being, because it is possible for the same accident to exist in the same thing or not to exist, and not only that, but for its contrary to exist there).⁶⁵

On Nature

The nature of each being is the principle of its motion and repose. The earth, for example, is moved [i.e., ploughed] to make it produce, but, so far as concerns its being moved from place to place, it is at rest, because it is not moved from place to place. Now, the principles and cause of its motion and repose—or that according to which it is of its nature thus moved and rests substantially, that is to say, naturally and not accidentally—is called φύσις, or nature, from its πεφυκέναι, or naturally having being and existing in such a manner. This is nothing other than substance, because it is from its substance that it has such a potentiality, that is to say, that of motion and repose. The substance, then, is the cause of its motion and repose. Now, φύσις, or nature, is so called from its πεφυκέναι, or naturally having being.

On Form

Form is the substance which has been, as it were, given form and made specific by the essential differences, and which signifies the most specific species. Thus, for example, the substance which has been given form and made specific by the animate and sentient body constitutes the animal. And again, when this last has taken on the rational and the mortal, it constitutes the species of man. It is precisely this most specific species which is called form, an informed substance, as it were.

And so the holy Fathers apply the terms substance, and nature, and form to the most specific species, and they say that substance and nature and form are the same thing, namely, the most specific species. And the individuals coming under the same most specific species they say to be of the same substance, of the same nature, of the same species, of the same genus, and of the same form. On the other hand, they say that the most specific species are of different substance, of different nature, of different species, of different genus, and of different form. This is because it is impossible for a species not to be of a different substance and of a different nature and of a different form from another species, or for a nature so not to differ from another nature, or for a substance so not to differ from another substance.

One should know that it is impossible for one compound nature to be made from two substances, that is to say, from two natures, because it is impossible for logically opposed constituent differences to exist in the same thing. It is possible, however, for one compound hypostasis to be made from diverse natures, which is how man is made up of body and soul. Now, even though men are said to have one nature, the individual man is not said to be of one nature. This is because, on the one hand, the one nature of man is said to be compound, since all the compound hypostases of men come under one species; whereas, on the other hand, the individual man is not said to be of one nature, since each human hypostasis is made up of two natures—soul and body, I mean—which it preserves unconfused in itself, to which fact the separation caused by death bears witness.

On Hypostasis

The term hypostasis has two meanings. Sometimes it means simple existence. In this sense, substance and hypostasis are the same thing, which is why certain of the holy Fathers have said: ‘the natures, that is to say, hypostases.’⁶⁶ At other times, it means the existence of an individual substance in itself. In this sense, it signifies the individual, that which is numerically different, which is to say, Peter and Paul, or that certain horse.

Now, one should know that substance which is devoid of form does not subsist of itself, nor does an essential difference, nor a species, nor an accident. It is only the hypostases, the individuals, that is, that subsist of themselves, and in them are found both the substance and the essential differences, the species and the accidents. The simple substance, moreover, is found in the same manner in all hypostases: in inanimate and animate substances, in rational and irrational, in mortal and immortal. The essential differences, however, are one thing in inanimate substances and another in animate, one thing in rational and another in irrational, and, similarly, one thing in mortal and another in immortal. To put it simply, with the hypostases belonging to each most specific species, the same essential differences connect them one to another by reason of their substance, but they separate them from the hypostases of another species. In the same way, the accidents in these, that is, in the hypostases, are considered as separating each hypostasis from the other hypostases of the same species. For this reason the term hypostasis has been properly applied to the individual, since in the hypostasis the substance, to which the accidents have been added, actually subsists (ὑφίσταται).

On Person

A person is one who by reason of his own operations and properties exhibits to us an appearance which is distinct and set off from those of the same nature as he. When Gabriel, for example, was conversing with the Mother of God,⁶⁷ while he was one of the angels, he alone was present there and speaking. Thus he was by his presence and conversation in that place made distinct from the angels of the same substance with him. And when Paul spoke to the people from the stairs,⁶⁸ while he was one of the number of men, by his properties and operations he was distinct from the rest of men.

One should know that the holy Fathers used the term hypostasis and person and individual for the same thing, namely, that which by its own subsistence subsists of itself from substance and accidents, is numerically different, and signifies a certain one, as, for example, Peter, and Paul, and this horse. Hypostasis has been so called from its ὑφεστάναι, or subsisting.

On Enhypostaton

The enhypostaton, too, sometimes means existence in the strict sense. In this sense, we call not only simple substance but also the accident an enhypostaton, although, properly speaking, the accident is not an enhypostaton but heterohypostaton, or something which subsists in another. Sometimes it means the self-subsistent hypostasis, that is to say, the individual, which, properly speaking, is not an enhypostaton but a hypostasis and is so called. In its proper sense, however, the enhypostaton is either that which does not subsist in itself but is considered in hypostases, just as the human species, or human nature, that is, is not considered in its own hypostasis but in Peter and Paul and the other human hypostases. Or it is that which is compound with another thing differing in substance to make up one particular whole and constitute one compound hypostasis. Thus, man is made up of soul and body, while neither the soul alone nor the body alone is called a hypostasis, but both are called enhypostata. That which consists of both is the hypostasis of both, for in the proper sense hypostasis is that which subsists of itself by its own subsistence, and such this is called.

Again, that nature is called enhypostaton which has been assumed by another hypostasis and in this has its existence. Thus, the body of the Lord, since it never subsisted of itself, not even for an instant, is not a hypostasis, but an enhypostaton. And this is because it was assumed by the hypostasis of God the Word and this subsisted, and did and does have this for a hypostasis.

On Anhypostaton

The term anhypostaton is also used in two senses. Thus, it sometimes means that which has no existence whatsoever, that is to say, the non-existent. But it sometimes means that which does not have its being in itself but exists in another, that is to say, the accident.

The Division of Being

Being is divided⁶⁹ into substance and accident, not as genus into species, but as an equivocal term, or as those things which are derivative and relative.

The Division of Substance

Substance is a most general genus. It is divided into corporeal and incorporeal.

The corporeal is divided into animate and inanimate.

The animate is divided into sentient, or animal, zoophyte, and non-sentient, or plant.

The animal is divided into rational and irrational.

The rational is divided into mortal and immortal.

The mortal is divided into man, ox, horse, dog, and the like.

Man is divided into Peter, Paul, and all other individual men. These are individuals, hypostases, and persons.

Substance, then, is a most general genus. The body is a species of substance, and genus of the animate. The animate is a species of body, and genus of the sentient. The sentient animal is a species of the animate, and genus of the rational. The rational is a species of the animal, and genus of the mortal. The mortal is a species of the rational, and genus of man. Man is a most specific species, for he is a species of the mortal and at the same time the species of Peter and of Paul, and this is just what the holy Fathers meant by nature and form and substance.

The things which stand between the most general genus, or substance, and the most specific species, or man, ox, and so on, are subaltern genera and species. These are called essential and natural differences and qualities. They divide from those higher and are constituent of those lower; they make for the most specific species, which they constitute; and they distinguish nature from nature. Nature, moreover, is classed as most specific. Now, it has already been explained what substance and nature and form are, and what hypostasis and individual person are, and enhypostaton and anhypostaton. It has also been explained what the difference is between substance and accidents and how substance is superior to the accidents, because in it the accidents have their existence. Division itself has also been explained, as well as how substance differs from essential differences, namely, in that the substance made specific by them constitutes a certain sort of species and becomes of such a sort. It has furthermore been explained what nature is, and what form is, and what hypostasis, and person, and individual, and what the pagan writers thought about these, and what the holy Fathers thought, they who, as disciples of the truth and of the real philosophy, were rightly teaching teachers. So come, let us now speak of the things which are proper to substance.

It is a property of the substance not to be in a subject. Rather, the substance is a subject for the existence of the accidents, but itself does not have existence in another. This is also a property of essential differences. For the being in a subject neither saves when present nor destroys when absent and hence, being entirely accidental, does not enter into the definition. Essential differences, however, are not accidents, since they do save when present and when absent they do destroy. Thus it is that they also enter into the definition.

Still another property of substance is that of being predicated univocally, that is to say, of communicating both its name and definition. Another property is that of not having any contrary. Thus, to the stone, that is to say, to the substance of the stone, there is nothing contrary. The not admitting of more or less is likewise a property, being also a property of essential differences. Thus, man is certainly no more a substance than the horse, nor is an animal either, nor is the horse more a substance than man. And there is the property of being capable of admitting contraries successively, not in itself but in its modifications. By contraries I mean those which are accidents, because the substance can by no means receive any contraries that are substantial. Thus, the rational does not admit of being irrational, but the body is heated and then by modification cooled. And a soul sometimes acquires virtue and at other times vice.

Again on Things Which Are Generically the Same and Specifically the Same; and on Things Which Are Generically Different and Specifically Different; and on Things Which Are Hypostatically the Same and Things Which Are Numerically Different

Those things are generically the same which fall in the same category, as, for example, all things under substance—and in the same way with the other nine categories. One must know that in all there are ten categories, or most general genera, to which every absolute term is referred. They are as follows: (1) substance, as, for example, stone; (2) quantity, as, for example, two, three; (3) relation, as, for example, father, son; (4) quality, as, for example, white, black; (5) place, as, for example, in Damascus, and this is indicative of place; (6) time, as, for example, yesterday, tomorrow, and this is indicative of time; (7) state, as, for example, to be wearing a cloak; (8) position, as for example, to be standing, to be sitting; (9) action, as, for example, to burn; (10) passion, as, for example, to be burnt.

Those things are generically different which fall into different categories. Now, man and horse are generically the same, because they both belong to the category of substance; but man and knowledge are generically different, because man belongs to category of substance, while knowledge belongs to that of quality.

Those things are specifically the same which belong to the same species and agree in their essence. Peter, for instance, and Paul both belong to the same species, that of man. On the other hand, those things are specifically different which differ in species, that is, in their essence, as, for example, man and horse. The holy Fathers, however, use ‘generically the same’ and ‘specifically the same’ for the same things, namely, for things which are consubstantial, that is to say, are hypostases belonging to the same species.

Things are hypostatically the same when two natures are united in one hypostasis and have one compound hypostasis and one person, as in the case of soul and body. Those things are hypostatically and numerically different which, by the combination of their accidents, have set apart as distinct the peculiarity of their own hypostasis, or, in other words, those things which differ from one another in their accidents and have their existence individually. An example would be the individuals Peter and Paul, for the latter is one and the former another.

On Quantum and Quality

Quantity⁷⁰ is an accumulation of units—for the unit is not called quantity. When one unit and one unit are combined, they become two. Thus quantity is not division, but an accumulation and addition of units. For, to divide two into separate units of one, this is division; but to say that one and one are two, this, rather, is addition.

One must know that quantity is the measure itself and the number—that which measures and that which numbers. Quanta, however, are subject to number and measure; in other words, they are the thing that are measured and numbered. Of the quanta, some are discrete and some are continuous. The quantum is continuous when one thing is measured, as when we have one piece of wood two or three cubits long, or a stone, or something of the sort. Being one, it is measured, and for this reason it is called continuous. Quanta, however, are discrete which are separated from each other, as in the case of ten stones or ten palm trees, for these are separated from each other. These, then, are said to be numbered, unless because of their small size and great number they are measured by the measure of something of the sort, as is grain and the like.

Those things are defined as continuous whose parts touch upon a certain common limit. Thus, since a two-cubit piece of wood, that is to say, a piece two cubits long, is one piece, then the end of one cubit and the beginning of the other are one. For they are joined together and connected, and they are not divided from each other. Discrete things are those whose parts do not touch upon a common limit, as in the case of ten stones. For, should you count off five and five, they will have no common limit connecting them. And should you put something in between this five and that five, then there will be eleven and not ten. The terms themselves, continuous and discrete, make this plain.

Now, among the discrete quanta come number and speech. By number we here mean things which are counted. And things which are counted are absolutely discrete, as has been shown. Speech, too, is discrete, for speech is counted in its words, and its parts do not have a common connecting limit. Thus, if the sentences has ten words and you separate them into groups of five, then they have no common limit connecting them. And so, should you add something in the middle, then there will be eleven and not ten. In the same way, the word is counted in its syllables, since it has no common limit connecting them together. Take the word Socrates, for example. Between the syllable so and the syllable cra there is no common limit to connect them.

There are five continuous quanta: solid, surface, line, space, and time. One should know that the point is quantityless. This is because, being dimensionless, it is neither measured nor counted. The line, however, has one dimension, for it is length without breadth. Consequently, it is reckoned a continuous quantum. Since it is one, it is measured and its parts do have a common limit connecting them, which is the point in between. Now, ἐπιφάνεια, or surface, which is the outer part of the solid, is derived from φαίνεσαι, to appear. It has two dimensions: length and breadth. Since it is one, it is measured and its parts do have a common limit connecting them, which is the line in between. Moreover, one should know that the flat and even surface is called a plane, whereas that which is uneven and warped is just called a surface. The solid has three dimensions: length, breadth, and depth or thickness. Since it is one, it is measured and its parts do have a common limit connecting them, which is the plane. Space is the surface of the air, for the space in which you are is a surface, that is to say, the terminating surface of the air containing you. As a surface, it is reckoned a continuous quantum. Time also is measured in the past and the future, and its parts have a common connecting limit, which is the present instant of time. The instant is quantityless. Notice, then, that there are three things which are quantityless: the unit, the point, and the instant. The following seven are properly called quanta: (1) number; (2) speech; (3) time; (4) space; (5) line; (6) surface; and (7) solid.

Those things which are considered in quanta, such as action, movement, color, and the like, we call quanta per accidens. For example, if the action and motion take place over a great length of time, we speak of much action and much motion; if over a short space of time, then we speak of a little. Similarly, if there is whiteness in an extensive body, we say much white; if in a small body, then we say little.

Furthermore, the quantum may be finite or infinite. That, then, which can be measured or counted is finite. On the other hand, that is infinite which by some degree of excessiveness exceeds all measure and number. And the term great and very great are used in the sense of infinite, as when we speak of ‘the very great compassion of God’ or the ‘great mystery of the dispensation of God the Word.’

One should know that in the category of relation Aristotle places great and small, much and little, greater and smaller, less and more, double and half, and the like. Now, we say that under different aspects it is possible to place the same thing in different categories. Thus, when number and measure signify what has been explained above, they are put under quantity. On the other hand, when they have a mutual relation and are spoken of in relation to each other, then they are put under relation. Thus, ‘great’ is great in relation to ‘small’ and ‘double’ is double in relation to ‘half,’ and so on with the rest. In so far as the solid is physical, it comes under substance; but, in so far as mathematical, that is to say, measurable, it comes under quantity. And again, size and numerical quantity belong to quantity. Thus, size is measured and numerical quantity counted. And the term ‘how great’ refers to size, whereas ‘how many’ refers to numerical quantity.

There are three properties of the quantum, and they are called consequences. The first is the property of its not having any contrary in itself. Thus, in itself the solid has no contrary. However, in so far as it may happen to be white, it will have some contrary, namely, the black. One must furthermore know that there is no other number which is contrary to the number two, for, if there is any, there will be many of them. This is because all the other numbers would be contrary, in which case nature would have been unjust in opposing several contraries of one thing. For it is impossible for there to be several contraries to one thing.

The second property is that of not admitting of more or less. Thus, two palm trees cannot be more than two palm trees, and neither can two men be more than two men. That which has no contrary does not admit of more or less.

The third property is that to every quantum and to quantum alone there may be equal and inequal. Thus, a line may be equal to a line or not equal to it.

On Relatives

Those things are relative⁷¹ which, in what they themselves are, are said to belong to other things, or they are those which in any other way whatsoever are related to another thing. Now, they are said to belong to others, as a father to a son, for the father is necessarily said to be father of a son. On the other hand, they are related to another, as great is to little or much to little. For ‘much’ is not said to belong to ‘little,’ but to be ‘much’ in relation to ‘little.’

One should know that, whenever a thing is considered in itself, it is not relative. When, however, it has a habitude to another thing, then it is said to be relative. Here, then, is the essence of relatives and here is their hypostasis; namely, in their being said to be relative to another, that is to say, in their having a habitude to another. For it is their mutual habitude which makes things relative.

Some relatives are called by the same name, as a friend is a friend of a friend and as an enemy is an enemy of an enemy. Others are called by different names, as a father is a father of a son and as a teacher is a teacher of a pupil.

And again, some things are relative by excess, as the greater is greater than the less. Others are relative according to the relation of the thing discerning to the thing discerned, as scientific knowledge is the knowledge of that which is scientifically knowable. For science discerns that which is scientifically knowable, or, in other words, cognition discerns that which is knowable. And also, sensation is a feeling of the sensible object, placing is a placing of that which is placeable, standing is a standing of that which can stand, reclining is a reclining of that which can recline, and so on. Still others are relative according to potency and impotency. They are relative according to potency, as are the thing heating and the thing heated; according to impotency, or the privation of potency, as when we say that the eye does not have the power to see the sphere without stars. Others are relative according to the relation between the cause and the thing caused, as a father is a father of a son.

Proper to relatives is the fact that they may be affirmed convertibly. Thus, a friend is a friend of a friend, and the second is a friend of the first; a teacher is a teacher of a pupil, and a pupil is a pupil of a teacher. It is also proper to relatives that they go naturally together. Going naturally together means positing and being posited together, removing and being removed together. Thus, when there is a father there will definitely be a son; and when there is no father there will be no son. For, of whom would a son be, if there were no father? He who does not have a son will not be a father. And so the son is taken away when the father is; and the father is taken away when the son is. However, it is not his hypostasis which is taken away, but only the relation. Thus, even though he who was a son does remain, he does not remain as a son, because, if he does not have a father, then how will he be a son? Now, should we speak of a son of one deceased, either we should not be saying this in the proper sense but by a misuse of terms, or we should be saying it implying that the father, by reason of the immortality of his soul, had not died and become non-existent.

One should know that each category is a most general genus containing genera, subaltern species, differences which divide the genera and constitute the species, most specific species, and individuals. The constituent differences are not called essential except only in the category of substance, nor are the individuals called hypostases except only in the category of substance.

One should know that, in so far as substance itself is a genus and has habitude to another, it falls in the category of relatives. Thus, genus is genus of species and species are species of genus, and so they belong to the relatives.

Furthermore, things which are relative and convertible have their habitude either in things which are self-subsistent, or substances, or in things which are not, or accidents. Now, if the habitude is in self-subsistent things, then their relation will either be natural, like that of the father and son, or like that of slave and master, or artificial, like that of pupil and teacher, or by preference, like that of friend and friend or enemy and enemy. If, however, the habitude is not in self-subsistent things but in accidents, then the relation will either be natural, like that of double and half, or not natural. If it is not natural it will be either fortuitous, like that of slave and master, or artificial, like that of pupil and teacher, or by preference, like that of friend and friend or enemy and enemy. If, however, the habitude is not in self-subsistent things but in accidents, then the relation will either be natural, like that of double and half, or not natural (like that of great and small, for this relation is rather accidental than natural. Fortuity, however, and preference have no place with things that are not self-subsistent, unless it be that some self-subsistent thing that is possibly being affirmed accidentally should somehow appear as referable to another).⁷²

Now, relatives must first, as being considered in themselves, be put into one category. Then, as having a habitude to another, they must be put into the category of relatives. For a thing must first be without any relation, and then, afterwards, relation must be considered in it.

Habitude, which is the relation of one thing to another, is said to be a disposition, or affinity, of things which are predicated either of substance or of things connected with substance. Such may be either natural, or fortuitous, or artificial, or by preference.

On ‘Being of Such a Sort’ and Quality

Quality⁷³ is that by which things are termed as being of such a sort. And again, quality is that from which those things which share it derive their names. Thus, from ‘prudence’ one who possesses prudence is said to be ‘prudent,’ and he who enjoys ‘warmth’ is said to be ‘warm.’

One should know that τὸ ποιόν, or the being of such a sort, is more general than the quality. This is because the being of such a sort signifies both the quality and the thing which possesses it, that is, the quality, as ‘the warm,’ signifies that which has warmth. For, those who possess the quality are of such a sort, as, for example, those who have warmth are called ‘warm.’ And they who are warm are of such sort, but the warmth itself is a quality. Oftentimes, however, this quality is called of such a sort, and it is the same way with quantum and quantity.

Some of the qualities exist in animate and rational bodies, as various kinds of knowledge and virtues, sicknesses and health. And these are called habits and dispositions. Others exist in both animate and inanimate bodies, as heat and cold, form and shape, potency and impotency. Of these, some are potential and some actual. Now, if they are potential, they cause potency and impotency. If, on the other hand, they are actual, then either they will pervade the whole—as heat pervades the whole fire and as whiteness pervades all the milk and all the snow, and produce a passion and a passive quality—or they will be superficial and produce shape and form. There are, then, four kinds of quality: (1) habit and disposition, (2) potency and impotency, (3) affection and passive quality, and (4) shape and form.

Moreover, habit differs from disposition, because the habit does not change easily and is more permanent. Take prudence, for example, for one does not quickly change from prudence to imprudence. Similarly, knowledge may be a habit, too, for, when a person attains a thorough scientific understanding of something, this knowledge becomes firmly fixed in him and is hard to change. And the same is true of manliness, and discretion, and justice. Dispositions, however, are the easily moved and quickly changed, as, for instance, heat, cold, sickness, health, and the like. Thus, man is subject to these and he changes rapidly from hot to cold and from sick to healthy. These same, however—sickness, for example, health, and the like—will be habits if they are lasting and hard to change. Moreover, the term disposition is more general, because, since man is somehow ‘disposed’ to them, they are both called ‘dispositions.’ On the contrary, that which is easily changed is called ‘disposition’ only.

A second kind of quality is that of potency and impotency. These are not in act, but they have a natural aptitude or power, or a natural inaptitude. Thus, we say that a boy is potentially musical because this boy, even though he does not actually possess the art of music, has an aptitude for its attainment. The brute beast, however, is unmusical, because it neither possesses the art of music nor is capable of attaining it. And that which is hard has the potentiality of not being speedily divided into parts.

A third kind of quality is the passive quality and the affection, such as heat, cold, whiteness, blackness, and the like. Now, the affection, like the disposition, is easily lost, as when one might blush for shame or turn pale from fear. The passive quality, on the other hand, is not easily altered or changed. Moreover, some of the passive qualities do not originate in an affection, that is to say, they do not come from anything extrinsic, but are intrinsic to the substance. It is in this way that the heat is present in the fire and the sweetness in the honey. For, neither is the heat extrinsic to the fire nor is the sweetness to the honey; and, since such things do not have prior existence, neither did they acquire heat and sweetness subsequently. Nevertheless, as far as our senses are concerned, they produce the same affection. Thus, because the fire is hot, it heats us; and because the honey is sweet, it tastes sweet to us. Other passive qualities, however, do originate in some affection, or temperament. These do at times produce an affection in our senses, but this is not the same affection and quality that they have. Such, for example, are colors. Thus, a whiteness arising from some affection and temperament will produce an affection in the eyes, that is to say, perception in the eyes, opening up of the eyes, and lighting up of the eyes, but it will not make us white. Now, the passive quality which is not extrinsic will either be inherent in the entire species, as is heat in all fire, or will not be, as blackness in the Ethiopians—for not all men are black. What is more, this third kind of quality is considered not only in connection with the body, but also in connection with the soul.

A fourth kind of quality is shape and form. Shape occurs in both animate and inanimate bodies, but form only in the animate. Thus, if one were to use the terms form or well-formed in regard to inanimate bodies, this would not be a proper use but an abuse of terms. Now, the term shape is the more general, because, whereas form is also called shape, the shape of inanimate things is not called their form. Moreover, straightness, or erectness, and crookedness, or distortion, belong to quality.

One should know that in most cases the things which are of a sort derive their names from the qualities, as ‘hot’ comes from ‘heat.’ Some of them, however, get their names by equivocation. Thus, μουσική, or music, is the knowledge of music, but μουσική, or musical, is what the woman who possesses this knowledge is. Still others, though rarely, have names which are entirely different. Thus, ‘upright’ comes from ‘virtue’ with a different name, for he who is virtuous is also called ‘upright.’

One should know that the term affection is used in two ways. Thus, it may be said in respect to that which has already been affected, in which case it will come under the category of quality, as the garment which has already been made white is called white. Or it may be said in respect to that which is being affected now, in which case it will come under the category of passion, as with that which has not yet been made white but is being whitened now.

One should know that qualities are not corporeal but are incorporeal, for, if they were bodies, they would fall in the category of substance. All accidents, too, are incorporeal and in themselves have no existence, unless they are considered in the substance.

One should know that the essential qualities come under substance, for they are parts of substance and divide it, and they are included in the definitions of the species of substance. Now, under whatever category the whole comes, under that category all its parts will also come. Heaviness and lightness are either considered in masses, as with things which are being weighed, and come under quantity; or they are considered in a substance, as in the elements, say, of fire and earth, in which case they come under substance, because they are essential differences. It is the same with density and rarity, or tenuousness, for either they will belong to the essence of the elements and come under substance, or they will be non-essential and come under the category of position, as in garments, for in such a case they are positions.

Quality has three properties or attributes. The first is that it admits of contrariety. Thus, heat is contrary to cold and white to black. The second is that they admit of more and less, for, where there is contrariety, there will also be more and less. The more is an increase in intensity, and the less a decrease. Therefore, it is possible to say that this species is more white and less cold than this other species. The third attribute and that which is most proper is that of like and unlike. Nevertheless, one must know that shape has no contrary.

(One should know that not all privations are expressed negatively. On the contrary, they may also be expressed positively, as blindness and deafness. And again, not every species is termed positively, for some may also be termed negatively. For example, although ‘intemperance’ is a species, it has been given not a positive name but a negative one. Declaration is called an affirmation, as would be ‘he is noble.’ Denial, however, is a negation, as would be ‘he is not noble.’ But, when we say ‘lawless,’ the less implies negation just as much as does the particle not.)⁷⁴

Moreover, if this particular whiteness is said to be equal to this other, it is not as a quality that it is said to be equal, but as a quantity. And, since similarity and dissimilarity are considered in place, too, the equality of this surface to this other does not lie in its quantity but in its sharing quality.

On Action and Passion

One should know that action and passion, or the active and passive potencies, come under quality, but that which acts and which is acted upon is some substance acting in a certain way. To act, then, is to have within oneself a cause of action, whereas to be acted upon is to have in oneself and in another the cause of being acted upon, as with the creator and the creature. Thus, the creator has in himself the cause of creation, whereas on the other hand, the creature has in the creator the principle of creation and in its own self the suitability of being acted upon. By creator we here mean the artisan, such, for example, as the carpenter. And by creature we mean the matter subjected to the artisan, such, for example, as wood, for this last is subjected to the carpenter.

Of the things which come under action and passion some are said simply to make and to be made, as in the case of the practical arts, such as wood-working, metal-working, and the like. With these the thing made endures even after the maker has ceased making. Thus, when the builder has finished building, that which has been built by him endures. Other things one is said to do, in which case that which is done does not last after the doer has ceased doing. Thus, when the flute-player has stopped playing, the flute-playing does not keep on, but stops entirely. In the case of other things one is said to consider, as in the practice of astronomy and geometry, and in thinking, and the like. Then, again, there are those other kinds which are observed in such inanimate beings as fire, stone, wood, and so forth. The first of all these concern rational beings, whereas the very last kind concerns the inanimate and irrational beings. For the inanimate being does not act as the animate beings do, but as a body approaching a body.

This category has two properties. The first is that it admits of contrariety, for to heat is the contrary of to cool. The second is that it admits of more and less, for it is possible to heat more and to cool less; similarly, with being heated and being cooled.

Activity and passivity, then, are observed in all the categories: in substance, begetting and being begotten; in quantity, counting and being counted; in relation, doubling and being doubled; in quality, whitening and being whitened; in position, seating and being seated; in state, carrying and being carried; in place, containing and being contained; in time, containing and being contained in present, past, and future time.

On Position

Position is the having of a certain position in respect to another position, as, for example, the body which is in a certain position in relation to such another position, whether this last be lying, sitting, or standing. Position has three species, which are standing, sitting, and lying prone. Being erect constitutes standing. Partly lying and partly standing constitute sitting. And lying completely down constitutes lying prone. Position does not indicate either the thing in position or the place, but it does show the position itself of the thing in relation to the place.

Some of the things that have position have it naturally, as do the elements in their proper places—earth, for example; water, air, fire, and the like. Others have their position from being placed that way according to the rules of art, as a statue, a column, and the like. A further classification is that which says that some of the things having position are stationary, as the earth, while others are in motion, as the heavenly bodies. Still again, some of them are in position potentially, as, for example, things which are capable of moving to another place; while others are actually so, as those which are located somewhere.

On Place

The category of place indicates place. Thus, upon being asked where so-and-so is, we reply that he is in the house or in the city, and that indicates place. The species of the category of place correspond to the differences of places, which are: up, down, right, left, before, and behind.

On Time

The category of time shows time. Thus, when we are asked when this happened, we reply that it happened last year, or the year before last, both of which indicate time. There are as many species of the category of time as there are differences of time. These last are three: present, past, and future.

On Having, or State

Having⁷⁵ is a substance around a substance. It means containing or being contained without being any part of the other thing. Now, a tunic contains, and so does armor and the like, but a ring is contained, as well as any other small object of the sort. Both the thing containing and the thing contained must be substances, because, if the one were a substance and the other an accident, as would be knowledge and the knower, it would no longer fall into the category of having or state. The differences of having correspond to those of beings. Thus, there is either animate or inanimate, and we are said to have either an animate thing like a boy, a horse, and so forth, or an inanimate thing like a ring, a sandal, and the so forth. The word to have is used equivocally in several other meanings which we shall discuss later on.⁷⁶

On Opposites

Every opposite⁷⁷ is opposite either as a thing or as an assertion. If it is opposite as an assertion to an assertion, then it makes for affirmation and negation. Now, affirmation is the stating of what belongs to something, as, for example, ‘he is noble.’ Negation, on the other hand, is the stating of what does not belong to something, as, for example, ‘he is not noble.’ Both of these are called statements. If, however, the opposites are opposed as things, then either they are stated as of convertibles and constitute relatives which mutually induce and cancel each other, or they are not stated as of convertibles and do not have any relation. These last either change into each other, both being equally natural, and constitute such contraries as heat and cold; or the one changes into the other, whereas the other does not change. The former is natural, but the latter is unnatural and constitutes opposites by privation and habit, such as are sight and blindness. For sight is a habit, as from having, but blindness is a privation of the habit—the sight, that is.

Some contraries have no intermediate, whereas others have. Those which have no intermediate are those of which one or the other, that is to say, one of them, must necessarily be in their subject, or, in other words, in those things of which they are predicated. An example would be sickness and health in the subject body of an animal, for it is absolutely necessary for that body to have either sickness or health. By sickness we mean every disorder of the nature. Now, those which have an intermediate are those of which one or the other must not necessarily be in the subject, or in the things of which they are predicated. An example is that of white and black, for these are contraries, yet it is not at all necessary for one of them to be in the body, because it is not necessary for every body to be either white or black—there are gray bodies and tawny ones. There is indeed an exception to this in the case of opposites belonging by definition to some nature, as heat does to fire and cold to snow. Now, in the case of those contraries which have intermediates, some of the intermediates have names, as the mean between white and black is called gray. Others, however, have no names, as the mean between just and unjust has no name. In such a case the mean is made known by the negation of both of the opposites, as, for example, ‘neither just nor unjust.’

The contraries have certain accompanying peculiarities. The first is that evil is necessarily contrary to good, while to evil sometimes good is contrary and sometimes another evil. Thus, to moderation (immoderation is contrary, but to immoderation sometimes moderation⁷⁸) is contrary and sometimes stolidity. Stolidity is that state in which the affections are neither moved nor aroused. Thus, immoderation is a defect of moderation, while stolidity is an excess. And the excess is contrary to the defect. The second peculiarity is that it is impossible for contraries to be in the same individuals simultaneously, for it is impossible for Socrates to be well and sick at the same time, or for the same one of his members to be simultaneously hot and cold. The third peculiarity is that the contraries will be in the same subject, whether this be the same in genus, in species, or in number. They are in a subject which is the same in genus, as white and black in a simple body; the same in species, as health and sickness in an animal body; and the same in number, as is obvious—since the same body can be susceptible to contraries through a change of itself. The fourth is that contraries either come under the same genus, as white and black under color; or under contrary genera, as justice and injustice come under good and evil, which are contrary genera; or the contraries themselves are genera, as good and evil are contrary genera.

On Habit and Privation

The act of the one had and of the one having, as that of the arms and the armed or that of the wearer and the worn, is called a habit.⁷⁹ In the second place, habits are adventitious acts which are stable, whether physical or spiritual. Such would be physical, as heat in heated things, or spiritual, as knowledge. Thirdly, habit is that which one does not yet have, but for having which one does have a suitability. And this is the first meaning of being in potency. Fourthly, there is the natural quality or habit, as the heat of the fire and the dream of the sleeper. And this is the second meaning of being in potency and the first meaning of being in act, for the fire can burn but actually does not. Fifthly, habit is the perfect act, as with the sight which is now seeing and the heat which is now heating.

Privation is the absence of the habit. Thus, the privation of arms or clothing is opposed to the first meaning of habit. To the second meaning of habit is opposed the absence of extrinsic habits, as when the object which has been heated becomes cold. Opposed to the third meaning is the absence of that which the genus definitely does not have naturally, as we say that, while the child has a suitability for music, the fig tree definitely has not. Thus, the fig tree suffers a privation, because the genus of plants does not have any suitability for music. However, some one of the species may not have the suitability which the genus has. Thus, the animal has the suitability for seeing, but the mole, which is a species of animal, does not. Opposed to the fourth meaning of habit is the absence of habitual potency. And to the fifth is opposed the absence of the perfect act, or of the power, whether active or passive, and this is what we spoke of above as the opposition of opposites by privation and habit. This last has the three following characteristics: that what it is natural to have is not had at all, but is completely absent; that it is not had, when it is natural to have it; and that it is not had, where it is natural to have it. For example, we do not say that the stone is blind, for it is not of its nature to have the habit of sight. Neither do we say that the newly born puppy is blind, nor the new born child toothless, because is not of their nature to have these at this particular time. Neither do we say that the foot is blind, because it is not of the nature of the animal to have the habit of sight in its foot. So, when it is natural for one to have in these three ways, yet one does not, then this is called privation.

On Prior and Posterior

There are four distinct meanings of the term prior.⁸⁰ Of these, the most proper is the prior in time. In the case of animate beings, this is properly called ‘elder’ and with inanimate beings ‘older,’ but these terms are also used interchangeably, although improperly.

The second meaning is that of prior in nature. A thing having this kind of priority is implied in the positing of that to which it is prior, but its positing does not imply the other; when it is removed, the other is removed with it, but the removal of the other does not imply its removal. For example, the animal is prior to man. For, when there is an animal, although man is an animal, there will not necessarily be a man. But, if there is no man, there may still be an animal, because the horse and the dog are also animals. And if there is a man, there will necessarily be an animal, because man is an animal. If, however, there is no animal, then there will be no man at all, nor horse either, nor dog, nor anything else of the sort, because these are animals. (Thus far what concerns the second meaning.⁸¹)

The third is that of prior in order, as for example, when we say that a comes first and b second, and that then come the syllables and then the whole phrases.

The fourth is that of prior in dignity, as when we say that the bishop comes first and then the priest. Some, however, reject this sense, because it is possible for the first in order to be posterior in dignity.

The fifth is as when we speak of the cause and the caused. Thus Socrates is prior to the picture of himself, because he is causative of his own picture. The father, too, is prior to and greater than the son, because the father is causative of the son, in so far as the son is begotten of the father. It is for this reason that the blessed Gregory took in this sense what was said by our Lord in the Gospels, namely, ‘the Father is greater than I.’⁸²

Others add a priority in purpose, as, for example, the wall is prior to its foundations. However, this reduces to the fourth sense, which is that of priority in dignity. For, in this case, what is prior in intention is actually posterior. There are, moreover, as many kinds of posterior as there are of prior. Prior and posterior, and more and less, do not belong to the equivocal terms, but to those which are derivative.

On the Simultaneous

Simultaneous⁸³ is properly said of things whose beginnings of being were at the same time, as, for instance, when two individuals have been born at the same instant. This mode is opposed to the first meaning of prior. According to a second meaning, those things are simultaneous which exist together mutually without one being the cause of the other or caused by the other. Such are the double and the half, for these simultaneously exist together and simultaneously introduce each other. This mode is opposed to the second and fifth mode of prior. This is because in the second the things do not mutually introduce and remove each other, while in the fifth they are the cause and the caused. According to the third meaning, things which are logically divided are simultaneous. Logically divided species are those which result from the same division, as, for example, the rational and the irrational, which result from the division of animal. This mode is opposed to the first and the second modes of prior, and, to some extent, to the other three.

On Motion

Motion⁸⁴ is the actualization of potency as such. For example, the bronze is potentially a statue, because it can take on the form of the statue. Thus, the melting down, the molding, and the finishing, which are all motions, are an actualization of the metal which is potentially a statue. Consequently, motion will be considered in all the categories in which potency is considered. And in those in which potency is not considered, motion will not be considered either. Thus motion is considered in the categories of substance, quantity, quality, and place. In substance there is generation and destruction; in quantity there is increase and decrease; in quality, alteration; and in place, motion in a circle, which is called ‘circular,’ and motion in straight line, which is called ‘direct.’ There are, moreover, six kinds of direct motion: upward, downward, inward, outward, motion to the right, and motion to the left. And so with circular motion there are seven kinds of motion with respect to place.

Now, everything that is changed is changed either in itself, or in something within itself, or in something around itself. If this is in the thing itself, it will constitute generation and destruction. If, however, it is in something in the thing itself, this will either be in quantity, in which case it will constitute increase and decrease, or it will be in quality, in which case it will constitute alteration. And if it is in something around the thing, then it will constitute change in place, because place is neither the thing itself which is moved, nor is it anything in it; rather, it accompanies the things moved and is round about them.

Generation differs from destruction. This is because generation is the passing from non-being to being, for that comes into being, or is generated, which was not before. But with destruction it is just the reverse, for destruction is the change from being to non-being. And increase differs from decrease, because increase is the motion to a greater quantity, whereas decrease is that to a lesser. And again, there are opposite passions in alteration, as heat is opposed to cold and black to white. Thus, while destruction is opposed to generation, and increase to decrease, to alteration are opposed the corresponding opposite and rest. For cooling is opposed to heating and so is rest, because, when the object being heated attains its highest temperature and reaches a limit, then it rests and ceases being heated. In the same way, both the contrary motion and rest are opposed to change in place. For here, while there are contraries, such as upward and downward, there is also rest. Thus, should one throw a lump of earth up into the air, it will not start its downward motion before it first comes to rest. There is, however, no contrary motion to that of the heavens.

Moreover, it seems that alteration accompanies the other kinds of motion. This is because the thing which is being generated and that which is being destroyed, the thing which is increasing and that which is decreasing, and that which is being moved with respect to place are all definitely being altered. Although with the natural motions we do find the motion of alteration accompanying the others, nevertheless it is possible for a thing to be altered without, however, its being moved with any other motion. A stone, for example, may be heated and cooled, but it will neither increase nor cease to be. And in the same way with the rest. So, even if alteration does accompany the other motions, it is possible for it to be considered in itself, and for that reason the distinction between it and the others has been conceded.

Now, Aristotle does not call change a motion. Thus in Book 5 of his Physics he has demonstrated that generation and destruction are changes, but not motions, because motion takes place while the thing moved remains intact. However, although we said that there were two contraries to alteration and to change in place, namely the opposite motion and rest, one should know that it is not impossible for two things to be contrary to one thing in different respects. Thus, rest is like habit and privation, whereas the opposite motion is contrary in the proper sense as cooling is to heating.

On Having

The term to have⁸⁵ is used in eight senses. Thus, either it will be as with a habit and disposition, or with some other quality, for we are said to have knowledge and virtue. Or it will be as with a quantity, for a piece of wood is said to have a length of three cubits. Or it will be as with a substance around a substance, which is a most general genus, and which may be around the whole body like a tunic or around some part thereof like a ring on the finger. Or it will be as with a part in a whole, for we are said to have a hand. Or as with something in a receptacle, as we say that the jar has wine in it. Or as with possessions, for we are said to have a house or a field. Moreover, we are also said to have a wife, and the wife is said to have a husband, but this kind of things seems to be different from having, because it is convertible. Thus, it no more means the husband having a wife than a wife having a husband, because, both being equal and without difference, neither prevails over the other. And even though the owner has possessions and the possessions have an owner, this is not the same as in the case of a man having a wife and a wife having a husband. This is because the owner is absolute possessor and controller of his possessions. For this reason, it is more properly said that the owner has his possessions, whereas the possessions are had.

It is clear that having is one of the equivocal terms. There are, furthermore, some who say that there are as many differences of having as there are of action and passion. Thus, just as the things which act and are acted upon will either be animate or inanimate, so is it in this case—that which has and that which is had will either be animate or inanimate. How, then, will diverse genera have the same differences? Well, one can reply that having is either around the whole object or around a part thereof, and, again, this: that it is either a means of defense or an ornament.

On Statement, Negation, and Affirmation

One should know that the affirmation and the negation⁸⁶ are called statements. An affirmation is that statement which signifies what belongs to someone, or what someone is, for example: Socrates is wise, Socrates walks. A negation, on the other hand, is that which shows what does not belong to someone, or what someone is not, for example: So-and-so is not wise, so-and-so does not walk. Since a negation is opposed to every affirmation and an affirmation to every negation, the negation opposed to the affirmation and the affirmation opposed to the negation are called contradictions. One of these, moreover, must necessarily be false and one true.

On Term, Premise, and Syllogism

One should know that the purpose of the logical process is to make a clear statement of proof. The proof is a syllogism, and this syllogism is made up of two true premises and the conclusion. For example, if I want to prove that the soul is immortal, I say: ‘Everything that is perpetually in motion is immortal.’ This is a premise. Then I state a second premise: ‘The soul is perpetually in motion.’ Then the conclusion: ‘Therefore, the soul is immortal.’ Each part of the premise is called a term. A term is that into which every premise is resolved. For example, the premise goes: ‘Everything that is perpetually in motion is immortal.’ The part ‘everything,’ in so far as it is a part of the premise, is called a term. The ‘that is perpetually in motion’ is likewise called a term, as is the ‘immortal,’ and also the ‘is.’

One should know that all the premises must be true and that the conclusion must follow from the premises. For, if one of the premises were found to be false, or the conclusion, then it would not be a syllogism, but a paralogism. Furthermore, there is the simple word, the noun, the verbal phrase, the statement, and the term. In respect to their subject, these five do not differ from one another. Their difference is only relative. ‘Man,’ for example, as a simple significant term, is called a simple word; as subject, it is called a noun; as fulfilling the functions of a predicate, it is called a verbal phrase; as part of an affirmation and negation, it is called statement; and as part of a premise and of a syllogism, it is called a term.

One should know that in the premise, that is, in the affirmation and negation, the subject is called a noun, whereas the predicate is called a verbal phrase. For example, ‘the man walks’ is an affirmation. ‘The man’ is the subject, and is called noun. ‘Walks’ fulfills the function of a predicate, and is called a verbal phrase. In ‘Socrates is noble’ the subject is ‘Socrates’ and it is called a noun. The phrase ‘is noble’ fulfills the function of a predicate, and, as a part of the affirmation, is called a verbal phrase. Even though grammarians call ‘noble’ a complementary word, yet, to put it simply, whatever accompanies the ‘is’ is a verbal phrase.

It should be known that there is no difference between the following five terms: statement, premise, question, objection, and conclusion. Thus, when I simply state that ‘the soul is immortal,’ this is called a statement. But when it is taken as a part of a syllogism, then to say that ‘the soul is immortal’ is to state a premise. And when someone objects to the premise by saying: ‘How is it evident that the soul is immortal?—then such is termed an objection. Again, when we proffer it as an inquiry: ‘Now, is the soul immortal?’—this is called a question. When, finally, it has been deduced from the premises, it is called a conclusion. Take, for example, ‘the soul is perpetually in motion’ and ‘that which is perpetually in motion is immortal.’ From these premises it is deduced that ‘therefore the soul is immortal,’ and that is a conclusion.

Various Definitions

A premise is either a sentence denying something of something—which is a negation, as, for example, ‘Socrates does not laugh’; or it is a sentence affirming something of something—which is affirmation, as ‘Socrates does laugh.’ A term is that into which the premise is resolved. A syllogism is a discourse in which, when two things have been laid down, or acknowledged as true, a third necessarily follows from the things laid down, and follows because of them. Thus, because of the premises laid down, the conclusion is made without any need of external support. A question is an examination directed to acceptance or rejection, that is to say, denial or approval, with respect to knowledge and speculation. An interrogation is an inquiry requiring a detailed, or full answer. Now, the inquiry differs from the interrogation in that the answer to it is short, that is to say, is given in a few words, whereas the answer to the interrogation is long and requires many words. That which is in the form of question and answer is said to be in dialogue form. An objection is that which from the very beginning upsets the assertion, while antiparastasis accepts the assertion as true but shows how it has no bearing on the matter at hand. A lemma is that which has been taken for granted for the purpose of proving something. A heresy is a persuasion, or opinion, held by several persons in agreement with each other but at variance with others. A common opinion is one acknowledged by everyone, as, for example, that the sun exists. A thesis is an unusual assumption made by some person who is distinguished for his wisdom, or, in other words, it is an extraordinary theory like that of Parmenides, who held that being is one, or that of Heraclitus, who held that all things are in motion.

That is common which is observed in several or is predicated of several. There are four ways in which a thing is said to be common: (1) either as that which is divisible into parts, as land is parcelled out; (2) or as that which is indivisible but is used in common, as one slave or one horse belonging to two masters and now carrying out the orders of one and now those of the other; (3) or as that which becomes private by reservation but reverts again to the common use, as a seat at the theatre or a place at the baths; (4) or, finally, as to that which is indivisible, yet proposed to the same common consideration, as the voice of the herald. It is in this last sense that the expression ‘having a common name’ is to be understood with respect to equivocal and univocal terms. That is of itself which does not belong accidentally to something, but primarily and essentially, as does the rational to man. And that is universal which signifies several individual things, as do the terms man, animal, and substance. That is accidental which may or may not exist in something, as sickness or health in a man. The term to make is used in connection with the creative arts, where the thing done endures—as in the case of carpentry and the like. Thus, after the process of making the couch remains. On the other hand, the term to do is used in cases where the work does not endure, that is to say, where the result of the work does not endure, as in the case of flute-playing and dancing. Speculation is that which we call thinking, the practice of astronomy and geometry, and so on.

Correct speech exhibits two kinds of excogitation (ἐπίνοια). Thus there is that which is, as it were, a certain extra thinking out and consideration by which the general concept and unanalyzed knowledge of things are unfolded and made fully clear. Such is the case when that which to the senses appears simple is by careful investigation discovered to be manifold and varied. Man, for example, appears to be simple, but by excogitation he is discovered to be twofold—made up of a body and a soul. The other kind is that which, through a combination of the sensitive and imaginative faculties, from things which exist makes up and imagines things which do not and produces a figment of thought. Such is the concoction of fabulous centaurs, sirens, and tragelaphs. For this kind has taken parts of wholes and, quite freely and arbitrarily composing something else from these parts, has in thought and speech given form to things never seen in reality and substance. Then, by taking on material form, also, it has produced idols. And this is called simple excogitation.

(When one predicates the things contained in something of the thing contained, we have redundance. For example, both the animal and the biped are included in man, and in Socrates both the cultivated and the white. If, then, one should predicate these of man or Socrates and say that man is a two-footed animal or that Socrates is something white and cultivated, he would be talking redundantly by saying the same thing several times over. This is redundance, because these things are contained in man and in Socrates, so that by mentioning the latter one also reveals the former.

Nearness is a relation, and so is fondness, that is to say, friendship, and so is possession, and participation, and connection. Furthermore, we call relation that connection, habitude, and disposition to which and such a thing which is expressed by ‘whither,’ ‘whence,’ and ‘where.’ It must still further be known that among four men there are six relations: that of the first to the other three, which makes three relations; that of the second to the last two, which makes five; and that of the third to the last one. Thus, it turns out that the four have six relations. And among five men there are ten relations.)⁸⁷

A union is brought about in various ways. Thus, it may be by mixture, as in the case of several kinds of flour being put together and mixed. Or it may be by welding, as with copper and lead; or by joining, as with stones and wood; or by fusion, as with molten materials like wax, pitch, and the like, and as with molten metals like gold and silver and such; or by mingling, as with liquids such as wine and water, or wine and honey. It may be by coalescence, as in the case of things which have been separated and then put back together again—for example, a brand taken from a fire and then put back.

Union by composition is the mutual association together of the parts without detriment to any of them, as in the case of the soul and the body. This is what some have called a blending together, that is to say, a knitting together. One must know, however, that while some of the Fathers did not accept the term blending in connection with the Mystery of Christ, union by composition was acceptable to them all. This union which is by composition is the hypostatic union. That thing which subsists of two natures is one hypostatically. And again, that is one hypostatically which is perceived to be of two things but in one person. Still again, the union is hypostatic when the nature joins with another hypostasis.

Blending is an opposition of bodies and a mutual combination of qualities. And again, blending is an intimate union of bodies with an intermingling of their qualities. Blending is the concurrence of substances of different sorts accompanied by the interpenetration of the qualities associated with them.

That which is by apposition is also a union, and it is like that which is by joining.

Again, a union is apparent when one assumes the appearance of another and in his stead proffers the statements of this other about himself. A union may also be relative, as is that of a friend to a friend. And Nestorius thought up still other kinds of union—such, I mean, as those according to dignity, and equality in honor, and identity of will, and good pleasure, and the bearing of the same name.

It must further be known that in the hypostatic union the spiritual things are united to those things which can receive them, as are those which are corruptible. Once united, they remain unconfused, incorruptible, and unchangeable like things in juxtaposition. For such is the nature of spiritual things.

Further on the Hypostatic Union

One should know that the hypostatic union produces one compound hypostasis of the thing united and that this preserves unconfused and unaltered in itself both the uniting natures and their difference as well as their natural properties. Moreover, this has no hypostatic difference with itself, because those characteristic differences of the things uniting, by which each of them is distinguished from others of the same species, become its own. Thus it is with the hypostasis in the case of the soul and the body, for here one hypostasis is made of both—the compound hypostasis of Peter, let us say, or of Paul. This keeps in itself the two perfect natures—that of the soul and that of the body—and it preserves their difference distinct and their properties unconfused. And in itself it has the characteristic differences of each, those of the soul, which distinguish it from all other souls, and those of the body, which distinguish it from all other bodies. These, however, in no wise separate the soul from the body, but they unite and bind them together, at the same time marking off the one hypostasis composed of them from all other hypostases of the same species. Moreover, once the natures become hypostatically united, they remain absolutely indivisible. And this is so because, even though the soul is separated from the body in death, the hypostasis of both remains one and the same. For the constitution in itself of each thing at its beginning of being is a hypostasis. Therefore, the body remains, as does the soul; both always having the one principle of their being and subsistence, even though they are separated.

It is further necessary to know that it is possible for natures to be united to each other hypostatically, as in the case of man, and that it is also possible for the hypostasis to assume an additional nature. Both of these are to be observed in Christ, because in Him the divine and human natures were united, while His animate body subsisted in the pre-existent hypostasis of God the Word and had this for a hypostasis. It is, however, quite impossible for one compound nature to be made from two natures or for one hypostasis to be made from two, because it is impossible for contrary essential differences to exist together in one nature. This is because it is of the very nature of these to distinguish from each other the natures in which they exist. And again, it is impossible for things that have once begun to subsist in themselves to have another principle of subsistence, for the hypostasis is subsistence in self. It must further be known that in the Holy Trinity a hypostasis is the timeless mode of each external existence.

One should know, moreover, that whenever a compound nature is produced, the parts must be coincident and a new thing made from other things. This new thing will not preserve the thing of which it has been composed as such, but will change and alter them. Thus, when the body has been made up from the four elements, a new thing has been made out of other things, and this new thing is neither pure fire nor any of the other elements, nor is it so called. It is the same with the mule, which is bred from a horse and an ass, for it is neither a horse nor an ass, nor it is so called. On the contrary, it is a new thing produced from others and which does not preserve unconfused and unchanged either one of those things of which it is composed.

Six Definitions of Philosophy

Philosophy⁸⁸ is knowledge of things which are in so far as they are; that is to say, a knowledge of their nature. Philosophy is a knowledge of divine and human things. Philosophy is a study of death, both that which is deliberate and that which is natural. Philosophy is a becoming like God, in so far as this is possible for man. Now, it is in justice, sanctity, and goodness that we become like God. And justice is that which is distributive of equity; it is not wronging and not being wronged, not prejudicing a person, but rendering to each his due in accordance with his works. Sanctity, on the other hand, is that which is over and above justice; that is to say, it is the good, the patience of the one wronged, the forgiving of them that do wrong, and, more than that, the doing of good to them. Philosophy is the art of arts and the science of sciences, for, since through philosophy every art is discovered, it is the principle underlying every art. Philosophy is love of wisdom. But, the true wisdom is God. Therefore, the love of God—this is the true philosophy.

Philosophy is divided into speculative and practical. Speculative philosophy is divided into theology, mathematics, and natural science. Mathematics is divided into arithmetic, geometry, and astronomy. Practical philosophy is divided into ethics, domestic economy, and political economy. Speculative philosophy, then, is the consideration of things that are incorporeal and immaterial, that is to say, it is the consideration of God, who primarily and properly is incorporeal and immaterial. But it also treats of angels, demons, and souls, which themselves are termed immaterial in comparison with the body, although in comparison with that which is immaterial in the true sense, namely, the divine, they are material. This, then, is theology. But consider the nature of material things, that is to say, of animals and plants, of stones and the like, that is what natural science is. And to consider those things which stand midway between these, which are now considered in matter and now outside of matter, and which stand midway between the immaterial and the material, this is mathematics. Thus, the number in itself is immaterial, but it is also found in matter, in grain, say, or wine, for we do speak of ten measures of grain and of ten pints of wine. This is also true of the other branches of mathematics. Practical philosophy governs manners and teaches how one must live in society. If it regards the guidance of the individual man, it is called ethics; if of the whole household, it is called domestic economy; and if of the entire state, political economy.

On the Four Dialectical Methods

One must know that there are four dialectical or logical methods.⁸⁹ That is by division which divides the genus into species by means of the intermediate specific differences. That is by the definition which defines the subject by the genus and the specific differences divided out by the method of division. That is by analysis which resolves the more composite thing into its simpler elements. Thus, the body is resolved into the humors; the humors, into the fruits; the fruits into four elements; the elements, into matter and form. That is by demonstration which proves the matter at hand by means of something intermediary. For instance, I have to prove that the soul is immortal, so I take an intermediary, namely, the being ever in motion, and I reason as follows: The soul is ever in motion. But, that which is ever in motion is immortal. Therefore, the soul is immortal.

It must further be known that syllogisms belong to the method by demonstration. And one must know that the analytical method is of three kinds. Thus, it may be natural, as in the example cited above. We also have logical analysis when we resolve the proposed syllogism into its proper form; and we have mathematical when we take the thing asked for granted and thence arrive at something which is acknowledged to be true and from which the proposition is proved. For example, let the question be: Is the soul immortal? I take for granted that which has been asked and I say: Since the soul is immortal, there is a reward for its bad and good actions. Now, if there is such a reward, then there is that which is passed judgment upon and that which passes judgment. But, if there is that which is judged and that which judges, then there is a provider and a providence. And so we have arrived at providence, which is acknowledged by everyone. From this point on I put things together and say: Since there is a providence and a dispenser of justice, there are also rewards. And since there are rewards, there is that which is judged. But, if there is that which is judged, then the soul is immortal.

Explanation of Expressions⁹⁰

Necessity is a cause of violence. In general, an element is that first thing from which something is made and to which it is ultimately reducible. In particular, however, an element is that of which a body is made and to which it is reducible—and such are fire, water, air, and earth. Fire is a body which is very rare, hot, and dry. Earth is a body which is very dry and heavy. Water is a body which is wet and very cold. Air is a body which is very wet and soft. Origination is a substantial motion from non-being to being. (Destruction and corruption is a motion from being to non-being.⁹¹) Increase is a motion in quantity by enlargement. Decrease is a motion in quantity by diminution. Alteration is a motion in quality by change. Motion is a motion from place to place. Rotation is a motion in the same place. Self-motion is the motion of the soul and it is also to be found in animals. Time is a measure of motion and a number of the prior and posterior in motion. Day is the passage of the sun over the earth, or the period of time during which the sun passes over the earth. Night is the shadow of the mass of the earth, or the time during which the sun is passing under the earth. A space of a night and a day is a revolution of the universe. A month is the space of time between one conjunction of the moon with the sun and the next conjunction. A year is the time it takes for the sun to pass through the cycle of the zodiac. A seasonable time is a time when things may be done successfully. Unseasonableness is the absence of a seasonable time for the successful prosecution of the thing required. An hour is either the fourth part of a year, or the twelfth part of the day, or the zenith of the spirit, or the prime of the body. Spring is the time during which wetness prevails. Summer is the time during which heat prevails. Autumn is the time during which dryness prevails. Winter is the time during which cold prevails. A barbed star is a starlike mass of fire having rays in front. A comet is a fiery mass of stars sending out rays round about like a long head of hair. A meteor is a starry shaft, that is to say, a beam sending rays upward. A fireball is an incandescent mass of fire. An iris is a majestic reflection of the sun in a hollow moist cloud. It appears circular like a ring, giving the impression of a star reflected in a mirror and it is caused by condensation of the air. A parhelion is a dense circular cloud resembling the sun, or it is a reflection of the sun in a dense and smooth cloud. A thunderbolt is a spiral blast which makes a fiery motion and is borne down from above in a flame of fire setting fire all around. A typhoon is a spiral movement of dark air drawn down to the earth from above. A waterspout is a spiral movement of radiant air borne down from above. A bolt of lightning is a thunderbolt apart from clouds. Hail is completely frozen water which has been frozen up above the earth. Ice is water which has been frozen on the earth. Snow is half-frozen water that comes down through the clouds onto the earth. Frost is entirely frozen water which has been frozen on the earth through the agency of another wet material. A rainstorm is a continuous fall of water excreted by clouds. A shower is a quantity of dew. Dew is moisture gathered into drops. Mist is the density which precedes the cloud. Vapor is a quantity of emanations on the earth. A lake is a large body of fresh water formed in hollows and low places. A sea is salty bitter water filling the cavities of the gulfs of the lowest part of the earth. A fountain is the gushing source of a spring, or outflowing water produced by a disturbance in the earth. An earthquake is a violent motion of wind entering in under the earth and forcing it to shake. A volcanic crater is an aperture, or vent, out of which flows subterranean fire. A lyre is a frame fitted with strings.

With the help of God, the philosophies of the most holy John of Damascus have been brought to completion.

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