SOCRATES: Then the opinions were true and false, and infected the pleasures and pains with their own falsity.
PROTARCHUS: Very true.
SOCRATES: But now it is the pleasures which are said to be true and false because they are seen at various distances, and subjected to comparison; the pleasures appear to be greater and more vehement when placed side by side with the pains, and the pains when placed side by side with the pleasures.
PROTARCHUS: Certainly, and for the reason which you mention.
SOCRATES: And suppose you part off from pleasures and pains the element which makes them appear to be greater or less than they really are: you will acknowledge that this element is illusory, and you will never say that the corresponding excess or defect of pleasure or pain is real or true.
PROTARCHUS: Certainly not.
SOCRATES: Next let us see whether in another direction we may not find pleasures and pains existing and appearing in living beings, which are still more false than these.
PROTARCHUS: What are they, and how shall we find them?
SOCRATES: If I am not mistaken, I have often repeated that pains and aches and suffering and uneasiness of all sorts arise out of a corruption of nature caused by concretions, and dissolutions, and repletions, and evacuations, and also by growth and decay?
PROTARCHUS: Yes, that has been often said.