ARISTOTLE

Thinking about Substances

Aristotle sets out theories of existence in the Categories and the Metaphysics. It is traditionally thought that the Categories is an early effort he later revises in the Metaphysics.

• Categories 2.1a

Of the beings: some are said of a subject but are not in any subject. Man is said of a subject, this or that man, but is not in any subject. Some are in a subject but are not said of any subject. By in a subject, I mean what is in something, not as a part, and cannot exist separately from what it is in. For example, the knowledge-of-grammar is in a subject, the soul, but is not said of any subject; and the white is in a subject, the body (for all color is in a body), but is not said of any subject. Some are both said of a subject and in a subject. For example, knowledge is in a subject, the soul, and is also said of a subject, knowledge-of-grammar. Some are neither in a subject nor said of a subject, for example, the this or that man or horse—for nothing of this sort is either in a subject or said of a subject. Things that are atomic and one in number (ἄτομα καὶ ἓν ἀριθμῷ) are, without exception, not said of any subject, but there is nothing to prevent some of them from being in a subject. Knowledge-of-grammar, for example, is one of the things in a subject.

Notes on the Text

The Categories is about terms, the parts of sentences. As part of his investigation, Aristotle discusses the reality terms signify. He divides reality (τὰ ὄντα, "the beings") according to what is "said of a subject" and what is "in a subject" The beings said of and not said of a subject are general and particular. The beings in and not in a subject are properties and objects.

In the sentence 'Socrates is a man,' the term 'man' signifies a general object. Man is a general object because it is said of subject but not in a subject. In the sentence, it is said of Socrates.

Man is not in any subject because the existence of man does not depend on any subject.

The term 'Socrates' signifies a particular object. It is not said of anything in the sentence, and this is true generally. It is a part of reality that serves as a subject for predication.

Aristotle thinks that Socrates is also not in any subject. Aristotle goes on to say that beings neither said of nor in a subject are "primary substances" (πρῶται οὐσίαι).

In the sentence 'Socrates is white' the term 'white' signifies a particular property. It is in Socrates and is not said of any subject. This white, though, is a subject for the general property white.

• Categories 5.2a

A substance (οὐσία)--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. this or that man or this or that horse. The species in which the things primarily (πρώτως) called substances are, are called secondary (δεύτεραι) substances, as also are the genera of these species. For example, this or that man belongs in a species, man, and animal is a genus of the species; so these--both man and animal--are called secondary substances.

Notes on the Text

In addition to the individual men, Aristotle thinks that man exists. It is a "secondary substance."

He seems to rethink this ontology in the Metaphysics.

• Categories 5.2a

All the other things are 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.

Notes on the Text

The "primary substances" are somehow the foundation for existence. The idea is that everything else exists by being in the primary substances or said of them.

• Categories 5.2b

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 this or that 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.

Notes on the Text

It is more difficult to see why the secondary substances are substances at all.

• Categories 5.3b

Every substance seems to signify a this (τόδε τι). As regards the primary substances, it is indisputably true that each of them signifies a this; for the thing revealed is individual (ἄτομον) and one in number. 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 this, this is not really true; rather, it signifies a qualification (ποιόν τι)--for the subject is not, as the primary substance is, one, but man and animal are said of many things.

Notes on the Text

A primary substance is not a heap of things. It is one thing.

• Categories 5.4a

What is most characteristic of substance appears to be this: that, although it remains, notwithstanding, numerically one and the same, it is capable of being the recipient of contrary qualifications. Of things that are other than substance we could hardly adduce an example possessed of this characteristic. For instance, a particular colour, numerically one and the same, can in no wise be both black and white, and an action, if one and the same, can in no wise be both good and bad. So of everything other than substance. But substance, remaining the same, yet admits of such contrary qualities. One and the same individual at one time is white, warm or good, at another time black, cold or bad. This is not so with anything else.

Notes on the Text

It is unclear how Aristotle's ontology accommodates this fact about change.

It is possible for Socrates to become pale, for example, to not be pale at one moment and would be pale at a later moment, but it is unclear exactly what persists through this change.

Socrates is what persists, but he is a concrete object with the features that characterize such objects. So it seems that nothing persists through the change. What happens is that one concrete object goes out of existence and another very similar to it comes into existence.

This puzzle in part, it seems, makes Aristotle think again in the Metaphysics about substance. In the Metaphysics, concrete objects like "this man" or "this horse" are not primary substances. Substance is something more fundamental, and Aristotle considers whether it is form.

• Metaphysics VI.?.1026a

⊕ "Clearly then the study of things which are, qua being, also belongs to one science. Now in every case knowledge is principally concerned with that which is primary, i.e. that upon which all other things depend, and from which they get their names. If, then, substance is this primary thing, it is of substances that the philosopher must grasp the starting points and causes (τὰς ἀρχὰς καὶ τὰς αἰτίας)" (Metaphysics IV.?.1003b).

"There is a science which studies being qua being (ὂν ᾗ ὂν), and the properties inherent in it in virtue of its own nature (τὰ τούτῳ ὑπάρχοντα καθ᾽ αὑτό). This science is not the same as any of the so-called particular sciences, for none of the others contemplates being generally qua being; they divide off some portion of it and study the attribute of this portion, as do for example the mathematical science" (Metaphysics IV.1.1003a).

"And there are just as many divisions of philosophy as there are kinds of substance (οὐσίαι); so that there must be among them a first philosophy and one which follows upon it" (Metaphysics IV.?.1004a).

"First philosophy treats things which are both separable and immutable (χωριστὰ καὶ ἀκίνητα)" (Metaphysics VI.1.1026a). One might raise the question whether the first philosophy (πρώτη φιλοσοφία) is universal or deals with some one genus. ... If there is not some other substance besides those which are naturally composed, physics will be the primary knowledge; but if there is a substance which is immutable (ἀκίνητος), the science which studies this will be prior to physics, and will be first philosophy, and universal in this sense, that it is primary. And it will be the province of this science to study being qua being; what it is, and what the attributes are which belong to it qua being.

Notes on the Text

This, like much of Aristotle's Metaphysics, is difficult to understand.

The question is what first philosophy is about. Is about existence in general ("being qua being")? Or is it about some of the things that exist.

The answer is that it is about both.

First philosophy is about the beings whose existence is existence in general.

• Metaphysics VII.1.1028a ⊕

Being is said in many ways.... It signifies the what it is and some this (τόδε τι) and the quality or quantity or any other such category. Being is said in these ways, but it is evident that primary among them is the what it is, for this signifies the substance (for when we say what quality something is, we say that it is good or bad, not three-cubits or man, but when we say what it is, we say man or god, not pale or hot or three-cubits), and the other things are all said to be because some are quantities of what is, others are qualities, others again affections, still others something else.

Notes on the Text

The idea is that there are different answers to the "what is it?" question. When we say it is a man, we are signifying its substance. When we say it is good, we are signifying a quality of it. When we say it is three-cubits, we are signifying a quantity of it.

Substances, qualities, and quantities have ways of being or existing.

The way of being that characterizes substances is primary because qualities and quantities are (exist as) qualities and quantities of substances.

• Metaphysics VII.1.1028b

Long ago, now, and always, what is sought after and always puzzled over, what is being (τί τὸ ὄν), is the question what is substance (οὐσία). ... And so for us too our chief and primary and practically our only concern is to investigate what this way of being is.

Notes on the Text

Since the existence of substances is primary, the investigation is into what this way of being is.

The answer Aristotle seems to take most seriously is that it is the way of being of a form.

• Metaphysics VII.2.1028b

We must consider what things are substances; and whether there are any besides the sensibles, or not; and how these substances exist; and whether there is any separable substance (χωριστὴ οὐσία), and if so, why and how, or none besides the sensibles.

Notes on the Text

Are there any substances other than the sensible ones that are the objects of physics?

The sensible substances are forms in matter, human beings for example. Aristotle understands the soul to be the form of a living natural body and so takes psychology to be a part of physics.

If there are, their existence is somehow "separate" from the sensible substances.

• Metaphysics VII.1029a

We have now stated in outline what substance is—that it is not predicated of a subject (ὑποκειμένου), but is a subject of which the other things are predicated. But it is necessary not say this alone, for it is not enough. This is obscure, and it makes matter substance. ... But this is impossible; for it seems that separateness (τὸ χωριστὸν) and a this (τὸ τόδε τι) belong especially to substance. Hence it would seem that the form and the combination of form and matter are substance more than matter is. The substance, then, which consists of both—I mean of matter and form—may be dismissed, since it is posterior and obvious. Matter too is in a sense evident. We must investigaate the third, [the form,] for [whether or not] this [meets the conditions for being a substance] is the most perplexing.

Notes on the Text

To discover which things are substances (and thus are that in terms of which other things exist), we need to know what makes them substances.

A substances, Aristotle thinks, is (i) "not predicated of a subject, but is a subject of which the other things are predicated"; (ii) "separate," and "a this."

What he seems to mean is that a substance is a "subject" for the predication of properties, is "separate" from its properties, and is a one and so is a "this."

As candidates, Aristotle considers eliminates "matter (ὕλης)." Matter is not a "this."

He eliminates "the compound of form and matter."

Aristotle considers how form (εἶδος) meets the conditions for being a substance.

• Metaphysics XII.7.1071b

There must be some substance which is eternal and immutable. Substances are the primary reality, and if they are all perishable, everything is perishable. But motion cannot be either generated or destroyed, for it always existed; nor can time, because there can be no priority or posteriority if there is no time. Hence as time is continuous, so too is motion; for time is either identical with motion or an affection of it. But there is no continuous motion except that which is spatial, of spatial motion only that which is circular. ... If something acts, this will not be enough if its substance is potentiality; for there will not be eternal movement; for that which is potentially may possibly not be. There must be a starting-point (ἀρχὴν) whose substance (οὐσία) is actuality (ἐνέργεια).

Notes on the Text

Aristotle thinks there must be a first unmovable mover.

One premise in the argument is that there is no first or last moment of time. Aristotle thinks it follows from this premise that there is no beginning or end of movement.

Further, since time is continuous and is to be understood in terms of movement, it follows that movement is continuous. Only circular movement is continuous.

This continuous movement is the rotation of the stars in the first heaven.

What is the cause of this movement?

It cannot be something that can go out of existence.

Why?

Because given the eternity of time, something that can happen will happen. This would mean that continuous movement is not eternal, which we have seen is impossible.

So the cause must be a starting-point (ἀρχὴν) whose substance (οὐσία) is actuality (ἐνέργεια).

• Metaphysics XII.7.1072a

There is something which is eternally moved with an unceasing motion, and this unceasing motion is circular motion. This is evident not merely from argument, but also in fact [since we see the circular motion of the fixed stars]. The first heaven [the celestial sphere in which the fixed stars are located], then, must be eternal [so that there always was and will be the circular motion of the fixed stars as the first heaven rotates from east to west], and something must move it [so that it moves with circular motion]. And since that which is moved and moves is intermediate, there must be a mover which moves without being moved, being eternal, substance, actuality (ἀΐδιον καὶ οὐσία καὶ ἐνέργεια).

Notes on the Text

What moves the first heaven moves it without itself moving.

This is the first unmovable mover.

• Metaphysics XII.7.1072b

This is the starting point (ἀρχῆς) on which the heavens and nature depend. Its life is like the best which we temporarily enjoy. It must be in that state always, which for us is impossible... Holding in actuality (ἐνεργεῖ) is the intellect (νοῦς) the divine possesses, and contemplation (θεωρία) is that which is most pleasant and best. ... If, then, the state God (ὁ θεὸς) always enjoys is as great as that which we enjoy sometimes, it is marvelous; and if it is greater, this is still more marvelous. Nevertheless it is so. Moreover, life belongs to God. For the actuality (ἐνέργεια) of intellect (νοῦ) is life, and God is that actuality; and the essential actuality of God is life most good and eternal. We hold, then, that God is a living being, eternal, most good.

Notes on the Text

• Metaphysics XII.8.1074a

It is evident that there is only one heaven. For if there is to be a plurality (as there is of men), the principle of each must be one in kind but many in number. But all things which are many in number have matter (for one and the same definition applies to many individuals, e.g. that of man; but Socrates is one), but the primary essence has no matter, because it is complete reality. Therefore the first mover, which is immovable, is one both in formula and in number....

Notes on the Text