ce to another,
or goes round in the same place, is not that what is called motion?

THEODORUS: Yes.

SOCRATES: Here then we have one kind of motion. But when a thing,
remaining on the same spot, grows old, or becomes black from being
white, or hard from being soft, or undergoes any other change, may not
this be properly called motion of another kind?

THEODORUS: I think so.

SOCRATES: Say rather that it must be so. Of motion then there are these
two kinds, 'change,' and 'motion in place.'

THEODORUS: You are right.

SOCRATES: And now, having made this distinction, let us address
ourselves to those who say that all is motion, and ask them whether all
things according to them have the two kinds of motion, and are changed
as well as move in place, or is one thing moved in both ways, and
another in one only?

THEODORUS: Indeed, I do not know what to answer; but I think they would
say that all things are moved in both ways.

SOCRATES: Yes, comrade; for, if not, they would have to say that the
same things are in motion and at rest, and there would be no more truth
in saying that all things are in motion, than that all things are at
rest.

THEODORUS: To be sure.

SOCRATES: And if they are to be in motion, and nothing is to be devoid
of motion, all things must always have every sort of motion?

THEODORUS: Most true.

SOCRATES: Consider a further point: did we not understand them to
explain the generation of heat, whiteness, or anything else, in some
such manner as the following:--were they not saying that each of them
is moving between the agent and the patient, together with a perception,
and that the patient ceases to be a perceiving power and becomes a
percipient, and the agent a quale instead of a quality? I suspect that
quality may appear a strange and uncouth term to you, and that you
do not understand the abstract expression. Then I will take concrete
instances: I mean to say that the producing power or agent becomes
neither heat nor whiteness but hot and white, and the like of other
things. For I must repeat what I said before, that neither the agent
nor patient have any absolute existence, but when they come together
and generate sensations and their objects, the one becomes a thing of a
certain quality, and the other a percipient. You remember?

THEODORUS: Of course.

SOCRATES: We may leave the details of their theory unexamined, but
we must not forget to ask them the only question with which we are