Plato, Parmenides

[139a] “Then it does not change its place by going anywhere or into anything, nor does it revolve in a circle, nor change.” “Apparently not.” “Then the one is without any kind of motion.” “It is motionless.” “Furthermore, we say that it cannot be in anything.” “We do.” “Then it is never in the same.” “Why is that?” “Because it would then be in that with which the same is identical.” “Certainly.” “But we saw that it cannot be either in itself or in anything else.” “No, it cannot.” “Then the one is never in the same.” [139b] “Apparently not.” “But that which is never in the same is neither motionless nor at rest.” “No, it cannot be so.” “The one, then, it appears, is neither in motion nor at rest.” “No, apparently not.”

“Neither, surely, can it be the same with another or with itself; nor again other than itself or another.” “Why not?” “If it were other than itself, it would be other than one and would not be one.” “True.” “And, surely, if it were the same with another, it would be that other, and would not be itself; [139c] therefore in this case also it would not be that which it is, namely one, but other than one.” “Quite so.” “Then it will not be the same as another, nor other than itself.” “No.” “But it will not be other than another, so long as it is one. For one cannot be other than anything; only other, and nothing else, can be other than another.” “Right.” “Then it will not be other by reason of being one, will it?” “Certainly not.” “And if not for this reason, not by reason of itself; and if not by reason of itself, not itself; but since itself is not other at all, [139d] it will not be other than anything.” “Right.” “And yet one will not be the same with itself.” “Why not?” “The nature of one is surely not the same as that of the same.” “Why?” “Because when a thing becomes the same as anything, it does not thereby become one.” “But why not?” “That which becomes the same as many, becomes necessarily many, not one.” “True.” “But if the one and the same were identical, whenever anything became the same it would always become one, and when it became one, the same.” “Certainly.” “Then if the one is the same with itself, [139e] it will not be one with itself; and thus, being one, it will not be one; this, however, is impossible; it is therefore impossible for one to be either the other of other or the same with itself.” “Impossible.” “Thus the one cannot be either other or the same to itself or another.” “No, it cannot.” “And again it will not be like or unlike anything, either itself or another.” “Why not?” “Because the like is that which is affected in the same way.” “Yes.” “But we saw that the same was of a nature distinct from that of the one.” “Yes, so we did.”