Physics

...in the same way that being is a "this," and one is the form or the account, and further the opposite to this, which is privation. How these are two and how they are more has been said above. At first, it was said that only the opposites are principles, but later that something else must also underlie them, making them three. From what has been said now, it is clear what the difference between the opposites is, how the principles relate to one another, and what the subject is. Whether the form or the subject is substance is not yet clear. But that the principles are three, how they are three, and what their mode is, is clear. How many and what the principles are should be considered from these [arguments].

8 Let us now state how the puzzle of the ancients is solved in this way alone. For those who first sought truth and the nature of existing things according to philosophy were led astray, as if along some other path, pushed by their own difficulty. They claim that nothing of what exists is generated or destroyed, because it is necessary that what comes to be must come from either what is or what is not, and it is impossible for it to be from either of these. For what is cannot come to be (as it already is), and from what is not, nothing could come to be (as there must be something underlying it). And by extending this logic, they claim there is not even a plurality of things, but only being itself. They adopted this opinion because of the things mentioned; but we say that "coming from what is" or "coming from what is not," or what is not or what is doing or undergoing something, or whatever "this" comes to be, in one way does not differ from a physician doing or undergoing something, or something being or coming to be from a physician. Since this is said in two ways, it is clear that it also applies to what comes from being and to what being is doing or undergoing. For the physician builds, not as a physician, but as a builder, and becomes white, not as a physician, but as a dark man; but he heals and becomes non-physician i.e., ceases to act as a physician as a physician.