Dialogues of Plato - MobileReference [975]
THEODORUS: Nay, Socrates, not to examine thoroughly what the two parties have to say would be quite intolerable.
SOCRATES: Then examine we must, since you, who were so reluctant to begin, are so eager to proceed. The nature of motion appears to be the question with which we begin. What do they mean when they say that all things are in motion? Is there only one kind of motion, or, as I rather incline to think, two? I should like to have your opinion upon this point in addition to my own, that I may err, if I must err, in your company; tell me, then, when a thing changes from one place 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 concerned: Are all things in motion and flux?
THEODORUS: Yes, they will reply.
SOCRATES: And they are moved in both those ways which we distinguished, that is to say, they move in place and are also changed?
THEODORUS: Of course, if the motion is to be perfect.
SOCRATES: If they only moved in place and were not changed, we should be able to say what is the nature of the things which are in motion and flux?
THEODORUS: Exactly.
SOCRATES: But now, since not