lect a few of those which are
reckoned to be the principal ones, and consider their several natures
and their capacity of communion with one another, in order that if we
are not able to apprehend with perfect clearness the notions of being
and not-being, we may at least not fall short in the consideration of
them, so far as they come within the scope of the present enquiry, if
peradventure we may be allowed to assert the reality of not-being, and
yet escape unscathed.

THEAETETUS: We must do so.

STRANGER: The most important of all the genera are those which we were
just now mentioning--being and rest and motion.

THEAETETUS: Yes, by far.

STRANGER: And two of these are, as we affirm, incapable of communion
with one another.

THEAETETUS: Quite incapable.

STRANGER: Whereas being surely has communion with both of them, for both
of them are?

THEAETETUS: Of course.

STRANGER: That makes up three of them.

THEAETETUS: To be sure.

STRANGER: And each of them is other than the remaining two, but the same
with itself.

THEAETETUS: True.

STRANGER: But then, what is the meaning of these two words, 'same' and
'other'? Are they two new kinds other than the three, and yet always of
necessity intermingling with them, and are we to have five kinds instead
of three; or when we speak of the same and other, are we unconsciously
speaking of one of the three first kinds?

THEAETETUS: Very likely we are.

STRANGER: But, surely, motion and rest are neither the other nor the
same.

THEAETETUS: How is that?

STRANGER: Whatever we attribute to motion and rest in common, cannot be
either of them.

THEAETETUS: Why not?

STRANGER: Because motion would be at rest and rest in motion, for either
of them, being predicated of both, will compel the other to change into
the opposite of its own nature, because partaking of its opposite.

THEAETETUS: Quite true.

STRANGER: Yet they surely both partake of the same and of the other?

THEAETETUS: Yes.

STRANGER: Then we must not assert that motion, any more than rest, is
either the same or the other.

THEAETETUS: No; we must not.

STRANGER: But are we to conceive that being and the same are identical?

THEAETETUS: Possibly.

STRANGER: But if they are identical, then again in saying that motion
and rest have being, we should also be saying that they are the same.

THEAETETUS: Which surely cannot be.

STRANGER: Then being and the same cannot be one.

THEAETETUS: Scar