sophist   

Str. My notion would be, that anything which possesses any sort of
power to affect another, or to be affected by another, if only for a
single moment, however trifling the cause and however slight the
effect, has real existence; and I hold that the definition
of being is
simply power of
Theaet. They accept your suggestion, having nothing better of
their own to offer.
Str. Very good; perhaps we, as well as they, may one day change
our minds; but, for the present, this may be regarded as the
understanding which is established with them.
Theaet. Agreed.
Str. Let us now go to the friends of ideas; of their opinions,
too, you shall be the interpreter.
Theaet. I will.
Str. To them we say-You would distinguish essence from generation?
Theaet. "Yes," they reply.
Str. And you would allow that we participate in
generation, with the
body, and through perception, but we participate with the
soul through
in true essence; and essence you would affirm to be always the same
and immutable, whereas generation or becoming varies?
Theaet. Yes; that is what we should affirm.
Str. Well, fair sirs, we say to them, what is this participation,
which you assert of both? Do you agree with our recent definition?
Theaet. What definition?
Str. We said that being was an active or passive energy,
arising out
of a certain power which proceeds from elements meeting with one
another. Perhaps your cars, Theaetetus, may fail to catch their
answer, which I recognize because I have been accustomed to hear it.
Theaet. And what is their answer?
Str. They deny the truth of what we were just now, saying to the
aborigines about existence.
Theaet. What was that?
Str. Any power of doing or suffering in a degree however slight
was held by us to be a sufficient definition of being?
Theaet. True.
Str. They deny this, and say that the power of doing or
suffering is
confined to becoming, and that neither power is applicable to being.
Theaet. And is there not some truth in what they say?
Str. Yes; but our reply will be that we want to ascertain from
them more distinctly, whether they further admit that the soul
knows, and that being or essence is known.
Theaet. There can be no doubt that they say so.
Str. And is knowing and being known, doing or suffering,
or both, or
is the one doing and the other suffering, or has neither any share
in either?
Theaet. Clearly, neither has any share in either; for if they say
anything else, they will contradict themselves.
Str. I understand; but they will allow that if to know is active,
then, of course, to be known is passive. And on this view
being, in so
far as it is known, is acted upon by knowledge, and is therefore in
motion; for that which is in a state of rest cannot be acted upon,
as we affirm.
Theaet. True.
Str. And, O heavens, can we ever be made to believe that motion
and life and soul and mind are not present with perfect being? Can
we imagine that, being is devoid of life and mind, and
exists in awful