On Substance - "Categories" Ch. 5 - Aristotle

Primary and Secondary Substances Defined
2711. A substance—that which is called a substance most strictly, primarily, and most of all—is that which is neither said of a subject nor in a subject, e.g. the individual man or the individual horse. The species in which the things primarily called substances are, are called secondary substances, as also are the genera of these species. For example, the individual man belongs in a species, man, and animal is a genus of the species; so these—both man and animal—~-are called secondary substances.

Οὐσία δέ ἐστιν ἡ κυριώτατά τε καὶ πρώτως καὶ μάλιστα λεγομένη, ἢ μήτε καθ' ὑποκειμένου τινός λέγεται μήτε ἐν ὑποκειμένῳ τινί ἐστιν, οἷον ὁ τὶς ἄνθρωπος ἢ ὁ τὶς ἵππος. δεύτεραι δὲ οὐσίαι λέγονται, ἐν οἷς εἴδεσιν αἱ πρώτ 15 τως οὐσίαι λεγόμεναι ὑπάρχουσιν, ταῦτά τε καὶ τὰ τῶν εἰδῶν τούτων γένη· οἷον ὁ τὶς ἄνθρωπος ἐν εἴδει μὲν ὑπάρ χει τῷ ἀνθρώπῳ, γένος δὲ τοῦ εἴδους ἐστὶ τὸ ζῷον· 

Substance (ousia), most fully, is the purely individual existent subject (hupokeimenon). We cannot predicate the individual of or in any other thing, thus it exists in itself most fully and uniquely. This is called primary substance (protos ousia). 

Secondary substances (deutero ousia) refer to the common species (eidos) that are said of every primary substance. 

What is the difference between primary and secondary substances? 

The Subject, Name, and Definition are Implied in Predication
2#19. It is clear from what has been said that if something is said of a subject both its name and its definition are necessarily predicated of the subject. For example, man is said of a subject, the individual man, and the name is of course predicated (since you will be predicating man of the individual man), and also the definition of man will be predicated of the individual man (since the individual man is also a man). Thus both the name and the definition will be predicated of the subject. 

But as for things which are in a subject, in most cases neither the name nor the definition is predicated of the subject. In some cases there is nothing to prevent the name from being predicated of the subject, but it is impossible for the definition to be predicated. For example, white, which is in a subject (the body), is predicated of the subject; for a body is called white. But the definition of white will never be predicated of the body. 

φανερὸν δὲ ἐκ τῶν εἰρημένων ὅτι τῶν καθ ̓ ὑπο- 20 κειμένου λεγομένων ἀναγκαῖον καὶ τοὔνομα καὶ τὸν λόγον κατηγορεῖσθαι τοῦ ὑποκειμένου· οἷον ὁ ἄνθρωπος καθ ̓ ὑποκειμένου λέγεται τοῦ τινὸς ἀνθρώπου, καὶ κατηγορείται γε τοὔνομα, τὸν γὰρ ἄνθρωπον κατὰ τοῦ τινὸς ἀνθρώπου κατηγορήσεις καὶ ὁ λόγος δὲ τοῦ ἀνθρώπου κατὰ τοῦ τινὸς ἀν- 25 θρώπου κατηγορηθήσεται, ὁ γὰρ τὶς ἄνθρωπος καὶ ἄνθρωπός ἐστιν· ὥστε καὶ τοὔνομα καὶ ὁ λόγος κατὰ τοῦ ὑποκειμένου κατηγορηθήσεται. τῶν δ ̓ ἐν ὑποκειμένῳ ὄντων ἐπὶ μὲν τῶν πλείστων οὔτε τοὔνομα οὔτε ὁ λόγος κατηγο- ρεῖται τοῦ ὑποκειμένου· ἐπ ̓ ἐνίων δὲ τοὔνομα μὲν οὐδὲν κατ 30 λύει κατηγορεῖσθαι τοῦ ὑποκειμένου, τὸν δὲ λόγον ἀδύ νατον· οἷον τὸ λευκὸν ἐν ὑποκειμένῳ ὂν τῷ σώματι κατη- γορεῖται τοῦ ὑποκειμένου, λευκὸν γὰρ σῶμα λέγεται, ὁ δὲ λόγος τοῦ λευκοῦ οὐδέποτε κατὰ τοῦ σώματος κατηγορη- θήσεται. 

And so when we predicate a secondary substance of a subject, say Joey, then both the name of that secondary substance, "man," for example, and the statement of essence "rational animal", must be true of the subject, Joey. 

Now referring to accidents which are in a subject, we do not say they are predicated (kategorein) of the subject fully, either by name or by statement of essence. Sometimes people do predicate the name to a subject, such as a "white man," but the statement of essence, "whiteness itself" cannot be predicated of the subject.

What is the difference between a name "man", a definition "rational animal", and a subject "Joey"?

Why cannot accidents (things which are in a subject) be predicated fully of any particular subject? 

The Order of Knowing Versus the Order of Being
2234. All the other things are either said of the primary substances as subjects or in them as subjects. This is clear from an examination of cases. For example, animal is predicated of man and therefore also of the individual man; for were it predicated of none of the individual men it would not be predicated of man at all. Again, colour is in body and therefore also in an individual body; for were it not in some individual body it would not be in body at all. Thus all the other things are either said of the primary substances as subjects or in them as subjects. So if the primary substances did not exist it would be impossible for any of the other things to exist. 

Now besides individual substances themselves, all of the other three parts of the pre-categories can be said to be either of or in primary substances. 

Given the mode of our knowledge as human knowers, this is actually how we come to know the secondary substances and their accidents, through the individual existent primary substance or subject. (This is one major distinction between Aristotle's and Plato's philosophies). This also is making the distinction between the order of knowing and the order of being, between deductive and inductive methods. Here we are expressing that the order of our knowing comes inversely from the order of being. We must begin with the particulars of our experience inductively in order to eventually come to know the essence of commonalities in things, the higher form. 

What is the difference between the "order of knowing" and the "order of being"?

What is the difference between inductive and deductive reasoning? 

Sidenote - The Individual is Ineffable
This also leads to a very interesting reflection on the existing individual and the categories themselves by which we speak of things abstractly or logically. The logical categories represent patterns or commonalities by which we can speak of more than one thing at a time. Yet, it is only the individual that exists to us. And so we can see that the purely individual cannot be an idea. The individual is incommunicable and inaccessible to us directly. We have direct sensual knowledge of the individual, but we don't have a direct intellectual vision to know what an individual is. Rather, we only have indirect intellectual access through the categories of commonalities to speak. (We can begin to get at a singular universal in a round about way, but cannot penetrate the individual essentially in their singularity.) 

The proper name of someone is the closest thing we can have to an individualized intellectual knowledge. But this proper name only means something when we have spent time in their presence and have developed a connatural knowledge of them through lived experience. It also represents a sort of power over the individual, in that a proper name allows us to delimit them out from the multitude of being itself. And so it is believed that when we die that God has a name that directly corresponds to our deepest essence, ineffable and inexperiencable to us now, but we will recognize it. As St. Paul says, we our a mystery to ourselves. And so what is most real? The individual or the universal? In itself, one can make the argument that the essence is most real, for it contains in itself the source/cause/and completion of the whole type of thing. But in the mode of knowing to us the individual is most real. 

Properly Defining a Thing
Of the secondary substances the species is more a substance than the genus, since it is nearer to the primary substance. For if one is to say of the primary substance what it is, it will be more informative and apt to give the species than the genus. For example, it would be more informative to say of the individual man that he is a man than that he is an animal (since the one is more distinctive of the individual man while the other is more general); and more informative to say of the individual tree that it is a tree than that it is a plant. Further, it is because the primary substances are subjects for all the other things and all the other things are predicated of them or are in them, that they are called substances most of all. But as the primary substances stand to the other things, so the species stands to the genus: the species is a subject for the genus (for the genera are predicated of the species but the species are not predicated reciprocally of the genera). Hence for this reason too the species is more a substance than the genus. 

The species is closer than the genus to substance (the individual) because it is more specific and less broad in its classification. (As the primary substance being the most specific or individual.) Thus when we attempt to define a thing, it is more helpful to give species than genus. 

Why is it more helpful in defining a subject to give the species than just the genus? 

2522. But of the species themselves—those which are not genera—one is no more a substance than another: it is no more apt to say of the individual man that he is a man than to say-of the individual horse that it is a horse. And similarly of the primary substances one is no more a substance than another: the individual man is no more a substance than the individual ox.

While genus and species are relative terms and exist at many levels in the hierarchy of being, when we get closer to real existing substances, then we reach species which no longer can function as the next genera for more specific classifications. Then we reach an equivalence with an actually existing reality. For example, the difference between animal and man. Animal does not exist as such in the world, and can act as both a species of living thing and a genus for (types of living things), whereas a man does actually exist in the world and when we get any more specific we are not making more or less of a man. 

When does it mean when we have a species than cannot function as a genera for another grouping? 

22g. It is reasonable that, after the primary substances, their species and genera should be the only other things called (secondary) substances. For only they, of things predicated, reveal the primary substance. For if one is to say of the individual man what he is, it will be in place to give the species or the genus (though more informative to give man than animal); but to give any of the other things would be out of place-—for example, to say ‘white’ or ‘runs’ or anything like that. So it is reasonable that these should be the only other things called substances. Further, it is because the primary substances are subjects for everything else that they are called substances most strictly. But as the primary substances stand to everything else, so the species and genera of the primary substances stand to all the rest: all the rest are predicated of these. For if you will call the individual man grammatical it follows that you will call both a man and an animal grammatical; and similarly in other cases. 

Substances must refer to the individual (primary), or the closest genus and species (secondary), but not higher on the hierarchy as it gets too abstract. All accidents will be predicated in these. 

When defining a substance, where on the hierarchy of genera and species is most proper to go? 

397 It is a characteristic common to every substance not to be in a subject. For a primary substance is neither said of a subject nor in a subject. And as for secondary substances, it is obvious at once that they are not in a subject. For man is said of the individual man as subject but is not in a subject: man is not zz the individual man. Similarly, animal also is said of the individual man as subject but animal is not in the individual man. Further, while there is nothing to prevent the name of what is in a subject from being sometimes predicated of the subject, it is impossible for the definition to be predicated. But the definition of the secondary substances, as well as the name, is predicated of the subject: you will predicate the definition of man of the individual man, and also that of animal. No substance, therefore, is in a subject.

A substance, primary or secondary, is never an accident. The individual never is equivalent with the entirety of the concept. Neither can accidents, in their fullness, be predicated of a subject because the subject cannot exhaust the entirety of that accident. This man cannot be whiteness itself, though we often speak of this man being white. But the secondary substance is predicated of the primary substance in both definition and name. So animal can be predicated of John and he can be called an animal. 

3421. This is not, however, peculiar to substance; the differentia also is not in a subject. For footed and twofooted are said of man as subject but are not in a subject; neither two-footed nor footed is man. Moreover, the definition of the differentia is predicated of that of which the differentia is said. For example, if footed is said of man the definition of footed will also be predicated of man; for man is footed. 

The qualities of the differentia are also not exhausted by the subject but predicated of the subject in name and definition. 

3229. We need not be disturbed by any fear that we may be forced to say that the parts of a substance, being in a subject (the whole substance), are not substances. For when we spoke of things in a subject we did not mean things belonging in something as parts. 3233. It is a characteristic of substances and differentiae that all things called from them are so called synonymously. For all the predicates from them are predicated either of the individuals or of the species. (For from a primary substance there is no predicate, since it is said of no subject; and as for secondary substances, the species is predicated of the individual, the genus both of the species and of the individual. Similarly, differentiae too are predicated both of the species and of the individuals.) And the primary substances admit the definition of the species and of the genera, and the species admits that of the genus; for everything said of what is predicated will be said of the subject also. Similarly, both the species and the individuals admit the definition of the differentiae. But synonymous things were precisely those with both the name in common and the same definition. Hence all the things called from substances and differentiae are so called synonymously.

Accidents are not substances. When we have 

Contraries in Subjects? 
3>10. Every substance seems to signify a certain ‘this’. As regards the primary substances, it is indisputably true that each of them signifies a certain ‘this’; for the thing revealed is individual and numerically one. But as regards the secondary substances, though it appears from the form of the name—when one speaks of man or animal-—that a secondary substance likewise signifies a certain ‘this’, this is not really true; rather, it signifies a certain qualification, for the subject is not, as the primary substance is, One, but man and animal are said of’ many things. However, it does not signify simply a certain qualification, as white does. White signifies nothing but a qualification, whereas the species and the genus mark off the qualification of substance—they signify substance of a certain qualification. (One draws a wider boundary with the genus than with the species, for in speaking of animal one takes in more than in speaking of man.)

Primary substances are singular in nature, a "this" and is numerically one, whereas secondary substances apply to the many but are the qualifications that make a substance. Here we see implicitly the "principle of individuation" at work. 

Why does Aristotle call primary substances a "this" and numerically one, but not secondary substances? 

What is the principle of individuation? 

3>24. Another characteristic of substances is that there is nothing contrary to them. For what would be contrary to 'a primary substance? For example, there is nothing contrary to an individual man, nor yet is there anything contrary to man or to animal. This, however, is not peculiar to substance but holds of many other things also, for example, of quantity. For there is nothing contrary to fourfoot or to ten or to anything of this kind~—unless someone were to say that many is contrary to few or large to small; but still there is nothing contrary to any definite quantity.

Substance and quantity do not have proper contraries to themselves. There is not opposite of man, for example. 

Do substances have contraries of themselves? Why or why not? Why is a substance not more or less? 

3533. Substance, it seems, does not admit of a more and a less. I do not mean that one substance is not more a substance than another (we have said that it is), but that any given substance is not called more, or less, that which it is. For example, if this substance is a man, it will not be more a man or less a man either than itself or than another man. For one man is not more a man than another, as one pale thing is more pale than another and one beautiful thing more beautiful than another. Again, a thing is called more, or less, such-and-such than itself; for example, the body that is pale is called more pale now than before, and the one that is hot is called more, or less, hot. Substance, however, is not spoken of thus. For a man is not called more a man now than before, nor is anything else that is a substance. Thus substance does not admit of a more and a less. Numerically one and the same is able to receive contraries. In no other case could one bring forward anything, numerically one, which is able to receive contraries. For example, a colour which is numerically one and the same will not be black and white, nor will numerically one and the same action be bad and good; and similarly with everything else that is not substance. A substance, however, numerically one and the same, is able to receive contraries. For example, an individual man—-one and the same—becomes pale at one time and dark at another, and hot and cold, and bad and good. Nothing like this is to be seen in any other case.

Likewise, a substance cannot be more or less that substance. Joey is not more or less "man", for example. Other accidents, though, do admit this, such as being more or less white. Rather, substances can receive accidents which admit of change and contraries. 

4222, But perhaps someone might object and say that statements and beliefs are like this. for the same statement seems to be both true and false. Suppose, for example, that the statement that somebody is sitting is true; after he has got up this same statement will be false. Similarly with beliefs. Suppose you believe truly that somebody is sitting; after he has got up you will believe falsely if you hold the same belief about him. However, even if we were to grant this, there is still a difference in the way contraries are received. For in the case of substances it is by themselves changing that they are able to receive contraries. For what has become cold instead of hot, or dark instead of pale, or good instead of bad, has changed (has altered); similarly in other cases too it is by itself undergoing change that each thing is able to receive contraries. Statements and beliefs, on the other hand, themselves remain completely unchangeable in every way; it is because the actual thing changes that the contrary comes to belong to them. For the statement that somebody is sitting remains the same; it is because of a change in the actual thing that it comes to be true at one time and false at another. Similarly with beliefs. 

Contraries happen in substances because of change over time. While statements of facts and beliefs are not substances and thus do not change, nevertheless they are statements about substances and therefore admit change when the substances themselves change. Here Aristotle is also implicitly hitting on the Principle of Non-Contradiction. 

Substances can receive contraries and change over time, does this make previous statements about them contradictory? 

What is the principle of non-contradiction? 

Hence at least the way in which it is able to receive contraries—through a change in itself—would be distinctive of substance, even if we were to grant that beliefs and statements are able to receive contraries. However, this is not true. For it is not because they themselves receive anything that statements and beliefs are said to be able to receive contraries, but because of what has happened to something else. For it is because the actual thing exists or does not exist that the statement is said to be true or false, not because it is able itself to receive contraries. No statement, in fact, or belief is changed at all by anything. So, since nothing happens in them, they are not able to receive contraries. A substance, on the other hand, is said to be able to receive contraries because it itself receives contraries. For it receives sickness and health, and paleness and darkness; and because it itself receives the various things of this kind it is said to be able to receive contraries. It is, therefore, distinctive of substance that what is numerically one and the same is able to receive contraries. This brings to an end our discussion of substance.