Kitap 1
17
But presumably to be double a number is not the same as to be the number 2. Otherwise, one thing will be many—a consequence which actually followed in their system.i.e., the same number might be the first to which each of several definitions applied; then that number would be each of the concepts so defined. This much, then, can be learned from other and earlier schools of thought.
1
The philosophies described above were succeeded by the system of Plato,Compare Aristot. Met. 12.4.2-5. which in most respects accorded with them, but contained also certain peculiar features distinct from the philosophy of the Italians.
2
In his youth Plato first became acquainted with CratylusCf. Aristot. Met. 4.5.18. and the Heraclitean doctrines—that the whole sensible world is always in a state of flux,Plat. Crat. 402a (fr. 41 Bywater). and that there is no scientific knowledge of it—and in after years he still held these opinions. And when Socrates, disregarding the physical universe and confining his study to moral questions, sought in this sphere for the universal and was the first to concentrate upon definition, Plato followed him and assumed that the problem of definition is concerned not with any sensible thing but with entities of another kind; for the reason that there can be no general definition of sensible things which are always changing.
