PROTARCHUS: Then now, Socrates, let us proceed to the next point. SOCRATES: There are certainly many things to be considered in discussing the generation and whole complexion of pleasure. At the outset we must determine the nature and seat of desire. PROTARCHUS: Ay; let us enquire into that, for we shall lose nothing. SOCRATES: Nay, Protarchus, we shall surely lose the puzzle if we find the answer. PROTARCHUS: A fair retort; but let us proceed. SOCRATES: Did we not place hunger, thirst, and the like, in the class of desires? PROTARCHUS: Certainly. SOCRATES: And yet they are very different; what common nature have we in view when we call them by a single name? PROTARCHUS: By heavens, Socrates, that is a question which is not easily answered; but it must be answered. SOCRATES: Then let us go back to our examples. PROTARCHUS: Where shall we begin? SOCRATES: Do we mean anything when we say 'a man thirsts'? PROTARCHUS: Yes. SOCRATES: We mean to say that he 'is empty'? PROTARCHUS: Of course. SOCRATES: And is not thirst desire? PROTARCHUS: Yes, of drink. SOCRATES: Would you say of drink, or of replenishment with drink? PROTARCHUS: I should say, of replenishment with drink. SOCRATES: Then he who is empty desires, as would appear, the opposite of what he experiences; for he is empty and desires to be full? PROTARCHUS: Clearly so. SOCRATES: But how can a man who is empty for the first time, attain either by perception or memory to any apprehension of replenishment, of which he has no present or past experience? PROTARCHUS: Impossible. SOCRATES: And yet he who desires, surely desires something? PROTARCHUS: Of course. SOCRATES: He does not desire that which he experiences, for he experiences thirst, and thirst is emptiness; but he desires replenishment? PROTARCHUS: True. SOCRATES: Then there must be something in the thirsty man which in some way apprehends replenishment? PROTARCHUS: There must. SOCRATES: And that cannot be the body, for the body is supposed to be emptied? PROTARCHUS: Yes. SOCRATES: The only remaining alternative is that the soul apprehends the replenishment by the help of memory; as is obvious, for what other way can there be? PROTARCHUS: I cannot imagine any other. SOCRATES: But do you see the consequence? PROTARCHUS: What is it? SOCRATES: That there is no such thing as desire of the body. PROTARCHUS: Why so? SOCRATES: Why, because the argument shows that the endeavour of every animal is to the reverse of his bodily state. PROTARCHUS: Yes. SOCRATES: And the impulse which leads him to the opposite of what he is experiencing proves that he has a memory of the opposite state. PROTARCHUS: True. SOCRATES: And the argument, having proved that memory attracts us towards the objects of desire, proves also that the impulses and the desires and the moving principle in every living being have their origin in the soul. PROTARCHUS: Most true.