SOCRATES: I wonder whether you would agree with me about the origin of pleasure and pain.

PROTARCHUS: What do you mean?

SOCRATES: I mean to say that their natural seat is in the mixed class.

PROTARCHUS: And would you tell me again, sweet Socrates, which of the aforesaid classes is the mixed one?

SOCRATES: I will, my fine fellow, to the best of my ability.

PROTARCHUS: Very good.

SOCRATES: Let us then understand the mixed class to be that which we placed third in the list of four.

PROTARCHUS: That which followed the infinite and the finite; and in which you ranked health, and, if I am not mistaken, harmony.

SOCRATES: Capital; and now will you please to give me your best attention?

PROTARCHUS: Proceed; I am attending.