sophist   

there would be no absurdity in calling motion stationary.
Theaet. Quite right, -that is, on the supposition that some
classes mingle with one another, and others not.
Str. That such a communion of kinds is according to nature, we had
already proved before we arrived at this part of our discussion.
Theaet. Certainly.
Str. Let us proceed, then. we not say that motion is other than
the other, having been also proved by us to be other than
the same and
other than rest?
Theaet. That is certain.
Str. Then, according to this view, motion is other and also not
other?
Theaet. True.
Str. What is the next step? Shall we say that motion is other than
the three and not other than the fourth-for we agreed that there are
five classes about and in the sphere of which we proposed to make
enquiry?
Theaet. Surely we cannot admit that the number is less than it
appeared to be just now.
Str. Then we may without fear contend that motion is other than
being?
Theaet. Without the least fear.
Str. The plain result is that motion, since it partakes of being,
really is and also is not?
Theaet. Nothing can be plainer.
Str. Then not-being necessarily exists in the case of motion and
of every class; for the nature of the other entering into them all,
makes each of them other than being, and so non-existent; and
therefore of all of them, in like manner, we may truly say that they
are not-and again, inasmuch as they partake of being, that they are
and are existent.
Theaet. So we may assume.
Str. Every class, then, has plurality of being and infinity of
not-being.
Theaet. So we must infer.
Str. And being itself may be said to be other than the other kinds.
Theaet. Certainly.
Str. Then we may infer that being is not, in respect of as many
other things as there are; for not-being these it is itself one, and
is: not the other things, which are infinite in number.
Theaet. That is not far from the truth.
Str. And we must not quarrel with this result, since it is of the
nature of classes to have communion with one another; and if any one
denies our present statement [viz., that being is not, etc.], let
him first argue with our former conclusion [i.e., respecting the
communion of ideas], and then he may proceed to argue with what
follows.
Theaet. Nothing can be fairer.
Str. Let me ask you to consider a further question.
Theaet. What question?
Str. When we speak of not-being, we speak, I suppose, not of
something opposed to being, but only different.
Theaet. What do you mean?
Str. When we speak of something as not great, does the expression
seem to you to imply what is little any more than what is equal?
Theaet. Certainly not.
Str. The negative particles, ou and me, when prefixed to words, do
not imply opposition, but only difference from the words, or more
correctly from the things represented by the words, which
follow them.
Theaet. Quite true.
Str. There is another point to be considered, if you do not object.
Theaet. What is it?