Soc. And further let us add to these the pleasures of knowledge, if they appear to us not to have hunger for knowledge or pangs of such hunger as their source. Pro. I agree to that. Soc. Well, if men are full of knowledge and then lose it through forgetfulness, do you see any pains in the losses? Pro. Not by their inherent nature, but sometimes there is pain in reflecting on the event,
 when a man who has lost knowledge is pained by the lack of it. Soc. True, my dear fellow, but just at present we are recounting natural feelings only, not reflection. Pro. Then you are right in saying that we feel no pain in the loss of knowledge. Soc. Then we may say that these pleasures of knowledge are unmixed with pain and are felt not by the many but only by very few. Pro. Yes, certainly. Soc. And now that we have fairly well separated the pure pleasures and those which may be pretty correctly called impure, let us add the further statement that the intense pleasures are without measure and those of the opposite sort have measure; those which admit of greatness and intensity and are often or seldom great or intense we shall assign to the class of the infinite, which circulates more or less freely through the body and soul alike,
 and the others we shall assign to the class of the limited. Pro. Quite right, Socrates. Soc. There is still another question about them to be considered. Pro. What is it? Soc. What kind of thing is most closely related to truth? The pure and unadulterated, or the violent, the widespread, the great, and the sufficient? Pro. What is your object, Socrates, in asking that question? Soc. My object, Protarchus, is to leave no gap in my test of pleasure
 and knowledge, if some part of each of them is pure and some part impure, in order that each of them may offer itself for judgement in a condition of purity, and thus make the judgement easier for you and me and all our audience. Pro. Quite right. Soc. Very well, let us adopt that point of view towards all the classes which we call pure. First let us select one of them and examine it. Pro. Which shall we select? Soc. Let us first, if agreeable to you, consider whiteness. Pro. By all means. Soc. How can we have purity in whiteness, and what purity? Is it the greatest and most widespread, or the most unmixed, that in which there is no trace of any other color? Pro. Clearly it is the most unadulterated. Soc. Right. Shall we not, then, Protarchus, declare that this, and not the most numerous or the greatest,
 is both the truest and the most beautiful of all whitenesses? Pro. Quite right. Soc. Then we shall be perfectly right in saying that a little pure white is whiter and more beautiful and truer than a great deal of mixed white. Pro. Perfectly right. Soc. Well then, we shall have no need of many such examples in our discussion of pleasure; we see well enough from this one that any pleasure,
 however small or infrequent, if uncontaminated with pain, is pleasanter and more beautiful than a great or often repeated pleasure without purity. Pro. Most certainly; and the example is sufficient. Soc. Here is another point. Have we not often heard it said of pleasure that it is always a process or generation and that there is no state or existence of pleasure? There are some clever people who try to prove this theory to us, and we ought to be grateful to them. Pro. Well, what then? Soc. I will explain this whole matter, Protarchus,
 by asking questions. Pro. Go on; ask your questions. Soc. There are two parts of existence, the one self-existent, the other always desiring something else. Pro. What do you mean? What are these two? Soc. The one is by nature more imposing, the other inferior. Pro. Speak still more plainly. Soc. We have seen beloved boys who are fair and good, and brave lovers of them. Pro. Yes, no doubt of it. Soc. Try to find another pair like these
 in all the relations we are speaking of. Pro. Must I say it a third time? Please tell your meaning more plainly, Socrates. Soc. It is no riddle, Protarchus; the talk is merely jesting with us and means that one part of existences always exists for the sake of something, and the other part is that for the sake of which the former is always coming into being. Pro. I can hardly understand after all your repetition.