Metaphysics

​First, then, concerning those matters which we discussed first: whether it belongs to one science or to several to investigate all the classes of causes. For how could it belong to one science to know the principles if they are not contrary to one another? Further, all causes do not belong to many of the existing things. For in what way is it possible for there to be a principle of motion or the nature of the good for unmovable things, if indeed everything that is good in itself and through its own nature is an end, and is a cause in this way, namely, that for the sake of it other things both come to be and exist, and the end and that for the sake of which is the end of some action, and all actions involve motion? So that in unmovable things it would not be possible for this principle to exist, nor for there to be any good-in-itself. Therefore, in mathematics, too, nothing is demonstrated through this cause, nor is there any demonstration because something is “better” or “worse”; indeed, no one makes any mention of any such thing at all. As a result, because of this, some of the sophists, such as Aristippus, used to treat mathematics with contempt; for in the other arts, even the vulgar ones, such as carpentry and shoemaking, everything is said to be ”better” or “worse”, but the mathematical sciences make no mention of goods and evils. —But indeed, if there are several sciences of the causes, and a different one for a different principle, which of these must we say is the one we are seeking, or whom among those who possess them must we say is most of all a knower of the thing we are seeking? For it is possible for all the modes of causes to belong to the same thing: for example, in the case of a house, the source of motion is the art and the builder, that for the sake of which is the product, the matter is earth and stones, and the form is the definition. From what was defined long ago, then, there is a reason to call each of the sciences ”wisdom.” For insofar as one is most authoritative and commanding, and such that it is not right for the other sciences, like slaves, even to contradict it, the science of the end and of the good is of this character (for the sake of this, indeed, other things exist); but insofar as wisdom was defined as being of the first causes and of that which is most knowable, the science of substance would be of this character. For since we know the same thing in many ways, we say that he knows more who recognizes what the thing is by its being than by its not-being; and among these very people, one knows more than another, and most of all he who knows what it is, and not he who knows how much or of what sort it is, or what it is naturally active or passive in. Further, in other cases, too, we think that knowing each thing, even of those things of which there are demonstrations, belongs to us when we know what it is (for example, what is squaring, namely, the finding of a mean proportional; and similarly in other cases); but concerning generations and actions and all change, we think we know when we know the principle of motion. But this is different from and opposite to the end, so that it would seem to belong to a different science to investigate each of these causes.—But indeed, concerning the demonstrative principles also, whether they belong to one science or to several is a matter of dispute (and by demonstrative principles I mean the common opinions from which everyone demonstrates), for example, that it is necessary either to affirm or to deny everything, and that it is impossible at the same time to be and not to be, and all other such propositions: whether there is one science of these and of substance, or a different one; and if not one, which of the two must we call the one we are seeking now? Now, that they should belong to one science is not reasonable; for why is it more peculiar to geometry or to any other science to understand these? If, therefore, it belongs equally to any science whatever, but cannot belong to all, just as it does not belong to the others, so it is not peculiar to the science which recognizes substances to know about them. And at the same time, in what way will there be a science of them? For what each of these happens to be, we recognize even now (at any rate, other arts use them as being recognized). But if there is a demonstrative science of them, there will have to be some underlying genus, and some of them will be properties and others its axioms (for it is impossible for there to be demonstration of all things), since demonstration must proceed from certain things, concern a certain thing, and be of certain things. So that it follows that there is some one genus of all the things demonstrated, since all the demonstrative sciences use the axioms.—But indeed, if the science of substance and that concerning these principles are different, which of them is by nature more authoritative and prior? For the axioms are most universal of all and are principles of all things; and if they do not belong to the philosopher, to what other will it belong to investigate truth and falsehood concerning them?—And in general, is there one science of all substances or several? If, then, there is not one, of what sort of substance must we posit this science? But that there should be one of all is not reasonable.