Chapter 2 — The three principles of nature

Therefore, there are three principles of nature: matter, form, and privation. One of these, form, is that by reason of which generation takes place; the other two are found on the part of that from which there is generation. Hence matter and privation are the same in subject but they differ in definition, because bronze and what is shapeless are the same before the advent of the form; but for one reason it is called bronze and for another reason it is called shapeless. Wherefore, privation is not said to be a principle essentially, but rather a principle accidentally, because it is coincident with matter. For example we say that it is accidental that the doctor builds, because he does not do this insofar as he is a doctor but insofar as he is a builder, which is coincident with being a doctor in the same subject.

But there are two kinds of accidents: the necessary, which is not separated from the thing (for example, risible in man); and the non-necessary, which can be separated (for example, white from man). Thus, although privation is an accidental principle, still it does not follow that it is not necessary for generation, because matter is never entirely without privation. For insofar as it is under one form it has the privation of another, and conversely, just as there is the privation of fire in air and the privation of air in fire.

Also, we should note that, although generation is from non-existence, we do not say that negation is the principle but that privation is the principle, because negation does not determine a subject. Non-seeing can be said even of non-beings: for example, we say that the chimaera does not see, and we say the same of beings which are not apt to have sight, such as stones. But privation is said only of a determined subject: namely, that in which the habit is apt to come to be; for example, blindness is said only of those things which are apt to see.

Also, because generation does not come to be from non-being simply speaking, but from the non-being which is in some subject, and not in just any subject, but in a determined subject—because fire does not come to be from just any non-fire, but from such non-fire as is apt to receive the form of fire—therefore, we say that privation is the principle, and not negation. Privation differs from the other principles because the others are principles both in existence and in becoming. In order for a statue to come to be, there must be bronze; further, there must be the shape of the statue.

Again, when the statue already exists, it is necessary that these two exist. But privation is a principle in becoming, and not in existing, because until the statue comes to be it must not be a statue. For, if it were, it would not come to be, because whatever comes to be is not, except in successive things: for example, in time and motion. But from the fact that the statue already exists, the privation of statue is not there, because affirmation and negation are not found together, and neither are privation and habit. Likewise, privation is an accidental principle, as was explained above, but the other two are essential principles.

Therefore, from what was said, it is plain that matter differs from form and privation by definition. Matter is that in which the form and privation are understood, just as in bronze the shape and the shapeless is understood. Still, matter sometimes designates privation and sometimes does not designate privation. For example, when bronze becomes the matter of the statue, it does not imply a privation, because when I speak of ‘bronze’ in this way I do not mean what is undisposed or shapeless. Flour, on the other hand, since it is the matter with respect to bread, implies in itself the privation of the form of bread, because when I say ‘flour’ the lack of disposition or the inordination opposed to the form of bread is signified. Also, because in generation the matter or the subject remains, but the privation does not (nor does the composite of matter and privation); therefore, that matter which does not imply privation is permanent, but that which implies privation is transient.

We should notice, too, that some matter has a composition of form: bronze, for example. For, although it is the matter with respect to the statue, the bronze itself is composed of matter and form. Therefore, bronze is not called prime matter, even though it has matter. However, that matter which is understood without any form and privation, but rather is subject to form and privation, is called ‘prime matter’ by reason of the fact that there is no other matter before it. This is also called hyle. Also, because all knowledge and every definition comes by way of the form, prime matter cannot be defined or known in itself but only through the composite. Consequently, it might be said that that is prime matter which is related to all forms and privations as bronze is to the statue and the shapeless; and this is called first simply speaking. A thing can also be called prime matter with respect to some genus, as water with respect to aqueous solutions; this, however, is not first simply speaking because it is composed of matter and form. Hence it has a prior matter.

Note, also, that prime matter, and likewise form, is neither generated nor corrupted, because every generation goes from something to something. But that from which generation takes place is matter, and that in which generation terminates is form. Therefore, if matter and form were generated, there would be a matter of matter and a form of form, and so on forever. Hence, properly speaking, there is only generation of the composite.

Again, notice that prime matter is said to be numerically one in all things. But to be numerically one can be said in two ways, such as that which has a determined numerically one form, like Socrates. Prime matter is not said to be numerically one in this way, since it does not have in itself a form. Also, something is said to be numerically one because it is without the dispositions which would cause it to differ numerically. Prime matter is said to be numerically one in this way because it is understood without all the dispositions which would cause it to differ numerically.

Notice, likewise, that, although prime matter does not have in its definition any form or privation (for example, neither shaped nor shapeless is in the definition of bronze), nevertheless, matter is never completely without form and privation, because it is sometimes under one form and sometimes under another. Moreover, it can never exist by itself: for, since it does not have any form in its definition, it cannot exist in act, since existence in act is only from the form. Rather, it exists only in potency. Therefore, whatever exists in act cannot be called prime matter.