Aristotle's Metaphysics

Books VII and VII (Z and H): Highlights

Philosophy 201, Fall 1996

Dr. Cynthia Freeland


All readings are in Ancient Greek Philosophy, ed. Cohen, Curd, and Reeve

Metaphysics VII, Selections

Ch. 1. Being is spoken of in many ways (cf. the Categories). Substance is primary: in nature, in account (definition), and in knowledge.

Ch. 2. The most evident examples of substances are bodies, perhaps the simple bodies, and/or the limits/surfaces of bodies. We can ask many questions here: which things are substances? Are there non-perceptible substances?

Ch. 3. There are four main candidates for substance: essence, universal, genus, and subject. [This chapter focuses on subject, and seems to rule it out.] What is subject? It seems most of all to be substance: other things are said of it, and it is not said of other things. The subject may be the matter, the form, or the compound (bronze, shape of a horse, a bronze statue of a horse).

However: this is an inadequate answer to the question, what is substance?

Ch. 4. Let us next study essence: what a thing is said to be in its own right. First, we need to rule some things out. Essence is not just anything said in its own right. [This chapter is mainly devoted to ruling out unacceptable kinds of essences, the essences of non-substance things.]

Ch. 6. Is a thing the same as or different from its essence? [Answer Aristotle will give: the same as. Substance = essence, and a thing = its substance (a thing= its being); hence, a thing = its essence. Part of the problem building up here is that this means that two individuals, Socrates and Callias, who have the same essence, will be equal to each other.]

Ch. 10. How are parts of an account related to the thing? Definition is an account, something complex with parts. [The definition of man is rational animal; this is complex and has parts. Another way to consider this is to say that man's definition must include some parts, perhaps eating, reproducing, perhaps a brain, stomach, or perhaps fingers, etc. Aristotle leaves it a bit open at first here.] Parts of an account correspond with parts of the thing defined (if eating is part of the account of man as rational animal, since all animals eat, then it seems that stomach is part of the man.)

So does this mean that matter is part of the definition of substance? Yes and no. Aristotle seems to say that some functional sort of definition of matter may be part of the definition, but not actual materials. He uses the example of a syllable: the syllable "eat" has the letters "e" "a" and "t", but these are conceptual letters not material letters made of wax.

In a way, the body's parts like finger are prior to the compound, but in a way they are not (the finger cannot exist apart from the compound, so it is posterior to it). But perhaps some parts are more essential or simultaneous with the compound, such as heart or brain.

Ch. 15. Compound and form are different sorts of substance. Compounds perish, form does not. Because of this, forms, not particulars, are objects of knowledge. Particulars are not permanent enough; they cannot be defined. Nor can Ideas be defined: they are allegedly separable and particular. We would need some special idiosyncratic name to define them that picked out them alone. But the names we use are general and apply to more than one thing. Actually we cannot define anything that is unique or particular, even the sun and the moon.

Ch. 17.

Metaphysics H (VIII)

Ch. 1. Summary of where we've come so far (see points 1-7, p. 624). The subject is a substance: the matter, the form, or the composite. Only the composite is really subject to coming-to-be and perishing; it is separable (a "this") without qualification. Matter as well as the composite is substance.

Ch. 2. Substance that is matter is something potentially. So, we must describe the substance of perceptible things that is actually. This has something to do with differentiae (aspects of the matter that will determine how it is actually arranged or constituted into a thing).

There are many kinds of differentiae of matter--more than just the three Democritus mentioned in discussing his atoms. Material things are organized or unified, and differentiated, by such factors as combining or blending, tying together, gluing, nailing, their position, their time, their place, or other attributes.


These things are not substances, but substance-analogues. [They are somewhat more unified than mere ≥heaps.≤] In each case, the differentia in question is the analogue of actuality (form), or, what makes the thing what it is.

In the case of natural things, which are truly substances, the differentiae are what makes the matter actually be something. [Put another way: the form is what actualizes the matter of a thing into being what it really is. Your form of human being, or rational animality, makes your matter, flesh and blood and bones, into the thing you are, a person. Your form and matter are the same thing (a person): one actually (form), the other potentially (matter).]

Ch. 6.

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