Sophist 247d-249a
V. Then let's go back to questioning them (the earth giants, the
people who believe that only things that have body are) . It's
enough if they admit that even a small part of that which is
doesn't have body. They need to say something about what's common to
both it and the things that do have body, which they focus on when
they say that they both are. Maybe that will raise some
confusion for them. If it does, then think about whether they'd be
willing to accept our suggestion that that which is is
something like the following.
T. Like what? Tell me and maybe we'll know.
V. I'm saying that a thing really is if it has any capacity at all,
either by nature to do something to something else or to have even
the smallest thing done to it, even the most trivial thing, even if
it only happens once. I'll take it as a definition that those
which are amount to nothing other than capacity.
T. They accept that, since they don't ahve anything better to say
right now.
V. Fine. Maybe something else will occur to them later, and to us
too. For now let's agree with them on this much.
T. All right.
Visitor: Let's turn to the friends of the forms. You serve as their
interpreter for us.
Theaetetus: All right.
V: You people distinguish coming-to-be and being and say that they
are separate? Is that right?
T: "Yes."
V. And you say that by our bodies and through perception we have
dealings with coming-to-be, but we deal with real being by our souls
and through reasoning. You say that being always stays the same and
in the same state, but coming-to-be varies from one time to another.
T: "We do say that."
V. And what shall we say this dealing with is that you apply
in the two cases? Doesn't it mean what we said just now?
T; "What?"
V. What happens when two things come together, and by some capacity
one does something to the other or has something done to it. Or
maybe you don't hear their answer clearly, Theaetetus. But I do,
probably because I'm used to them.
T. Then what account do they give?
V. They don't agree with what we just said to the earth people about
being.
T. What's that?
V. We took it as a sufficient definition of beings that the
capacity be present in a thing to do something or have something
done to it, to or by even the smallest thing or degree.
T. Yes.
V. In reply they say that coming-to-be has the capacity to do
something or have something done to it, but that this capacity
doesn't fit with being.
T. Is there anything to that?
V. We have to reply that we need them to tell us more clearly
whether they agree that the soul knows and also that being
is known.
T. "Yes," they say.
V. Well then, do you say that knowing and being known are cases of
doing, or having something done, or both? Is one of them doing and
the other having something done? Or is neither a case of either?
T. Obviously neither is a case of either, since otherwise they'd be
saying something contrary to what they said before.
V. Oh, I see. You mean that if knowing is doing something, then
necessarily what is known has something done to it. When being is
known by knowledge, according to this account, then insofar as it's
known it's changed by having something done to it--which we say
wouldn't happen to something that's at rest.
T. That's correct.
V. But for heaven's sake, are we going to be convinced that it's
true that change, life, soul, and intelligence are not present in that
which wholly is, and that it neither lives nor thinks, but
stays changeless, solemn, and holy, without any understanding?