De principiis naturae

There are, then, three principles of nature: namely, matter, form, and privation. Of these, one — form — is that toward which generation tends, while the other two belong to that from which generation proceeds. Hence matter and privation are the same in subject but differ in account: for the very same thing which is bronze is unshaped before the coming of the form, but it is called bronze in one sense and unshaped in another. Hence privation is said to be a principle not per se but per accidens, since it coincides with matter — just as we say it is accidental that the doctor builds: for he builds not insofar as he is a doctor but insofar as he is a builder, which coincides with being a doctor in one subject. But accident is twofold: namely, the necessary kind, which is not separated from the thing, as risibility in man, and the non-necessary kind, which is separated, as whiteness from man. Hence, although privation is an accidental principle, it does not follow that it is not necessary for generation, since matter is never stripped of privation: for insofar as it is under one form, it has the privation of another, and conversely — as in fire there is privation of air, and in air privation of fire. And it should be known that, since generation is from non-being, we do not say that negation is a principle, but privation: for negation does not determine a subject for itself — 'does not see' can be said even of non-beings, as 'a chimaera does not see', and again of beings not apt by nature to have sight, as stones. But privation is said only of a determinate subject, in which a habit is apt by nature to come about — as blindness is said only of things apt by nature to see. And since generation does not come from non-being simply, but from the non-being which is in some subject — and not in just any, but in a determinate one (for fire does not come from just any non-fire, but from such non-fire as is apt by nature to receive the form of fire) — privation is therefore said to be a principle. But in this it differs from the others, since the others are principles both in being and in becoming: for a statue to come about, bronze must exist, and the figure of the statue must come last; and again, once it is a statue, these two must exist. But privation is a principle in becoming and not in being: for while the statue is becoming, it must not be a statue — if it were, it would not be becoming, since what becomes is not, except in successive things. But once it is a statue, there is no privation of statue in it, since affirmation and negation are not simultaneous, nor likewise privation and habit. Again, privation is an accidental principle, as explained above, while the other two are per se principles. From what has been said, then, it is clear that matter differs from form and from privation in account. For matter is that in which form and privation are understood — as in bronze, figure and the unshaped are understood. Sometimes matter is named together with privation, sometimes without privation: as bronze, being the matter of a statue, does not imply privation, since from saying 'bronze' nothing unarranged or unshaped is understood; but flour, being matter with respect to bread, implies in itself the privation of the form of bread, since from saying 'flour' is signified the unarrangement or disorder opposed to the form of bread. And since in generation the matter or subject remains, while privation does not — nor the composite of matter and privation — the matter which does not imply privation is permanent, while what implies it is transient. But it should be known that some matter has composition of form: as bronze, though it is matter with respect to a statue, is itself composed of matter and form; and therefore bronze is not called prime matter, since it has matter. But matter itself is what is understood apart from any form or privation, but as subject to form and privation, since before it there is no other matter. This is also called yle. And since all definition and all knowledge is through form, prime matter cannot be known or defined of itself, but only by comparison — as when we say that prime matter is what stands to all forms and privations as bronze stands to a statue and to the unshaped. And it is called simply first. Something can also be called prime matter with respect to some genus, as water is the matter of fusible things — though it is not simply first, since it is composed of matter and form, and hence has a prior matter. And it should be known that prime matter, and also form, is neither generated nor corrupted: for all generation is toward something from something, and what generation is from is matter, while what it is toward is form. If matter or form were generated, matter would have matter and form would have form, to infinity. Hence, properly speaking, generation belongs only to the composite. It should also be known that prime matter is said to be one in number in all things. But 'one in number' is said in two ways: as having one form determinate in number, as Socrates — and in this way prime matter is not said to be one in number, since it has no form in itself; and as being without the dispositions that make for difference in number — and in this way prime matter is said to be one in number, since it is understood apart from all the dispositions from which numerical difference arises. And it should be known that although matter has in its nature no form or privation — as in the account of bronze there is neither the shaped nor the unshaped — yet it is never stripped of form and privation: at one time it is under one form, at another under another. But of itself it can never exist, since having no form in its account, it has no actual being — actual being comes only from form — but is only in potency. And therefore whatever is actual cannot be called prime matter.