The flaw which he found in the Ionian theories was that they all assumed some want of homogeneity in the One, which was a real inconsistency. If you admit that a thing can change, you cannot maintain that it is eternal. The next point made by Melissus is somewhat peculiar. It is not easy to be sure what this refers to. Perhaps it is to the theory by which Anaxagoras explained perception.
Divisibility is excluded for the same reason.
These are the same arguments as Parmenides employed. 9, which is certainly quoted by Simplicius to prove this very point. If, however, our general view as to the character of early Greek philosophy is correct, the statement must seem incredible. And it will seem even more surprising when we find that in the Metaphysics Aristotle says that, while the unity of Parmenides seemed to be ideal, that of Melissus was material. Now the fragment, as it stands in the MSS. of Simplicius, puts a purely hypothetical case, and would most naturally be understood as a disproof of the existence of something on the ground that, if it existed, it would have to be both corporeal and one.