Theaetetus (159)

THEAET. It is impossible for it to be the same in anything, either in quality or in any other respect whatsoever, when it is wholly other.

SOC. Must we not, then, necessarily agree that such a thing is also unlike?

THEAET. It seems so to me.

SOC. Then if anything happens to become like or unlike anything—either itself or anything else—we shall say that when it becomes like it becomes the same, and when it becomes unlike it becomes other?

THEAET. We must.

SOC. Well, we said before, did we not, that the active elements were many—infinite in fact—and likewise the passive elements?

THEAET. Yes.

SOC. And furthermore, that any given element, by uniting at different times with different partners, will beget, not the same, but other results?

THEAET. Certainly.

SOC. Well, then, let us take me, or you, or anything else at hand, and apply the same principle—say Socrates in health and Socrates in illness. Shall we say the one is like the other, or unlike?

THEAET. When you say Socrates in illness do you mean to compare that Socrates as a whole with Socrates in health as a whole?

SOC. You understand perfectly; that is just what I mean.

THEAET. Unlike, I imagine.

SOC. And therefore other, inasmuch as unlike?

THEAET. Necessarily.

SOC. And you would say the same of Socrates asleep or in any of the other states we enumerated just now?

THEAET. Yes.

SOC. Then each of those elements which by the law of their nature act upon something else, will, when it gets hold of Socrates in health, find me one object to act upon, and when it gets hold of me in illness, another?

THEAET. How can it help it?

SOC. And so, in the two cases, that active element and I, who am the passive element, shall each produce a different object?

THEAET. Of course.

SOC. So, then, when I am in health and drink wine, it seems pleasant and sweet to me?

THEAET. Yes.

SOC. The reason is, in fact, that according to the principles we accepted a while ago, the active and passive elements produce sweetness and perception, both of which are simultaneously moving from one place to another, and the perception, which comes from the passive element, makes the tongue perceptive, and the sweetness, which comes from the wine and pervades it, passes over and makes the wine both to be and to seem sweet to the tongue that is in health.

THEAET. Certainly, such are the principles we accepted a while ago.

SOC. But when it gets hold of me in illness, in the first place, it really doesn’t get hold of the same man, does it? For he to whom it comes is certainly unlike.

THEAET. True.

SOC. Therefore the union of the Socrates who is ill and the draught of wine produces other results: in the tongue the sensation or perception of bitterness, and in the wine—a bitterness which is engendered there and passes over into the other; the wine is made, not bitterness, but bitter, and I am made, not perception, but perceptive.

THEAET. Certainly.