realization of his desire, intimates his wish to have it by a nod of assent, as if he had been asked a question?

Very true.

And what would you say of unwillingness and dislike and the absence of desire; should not these be referred to the opposite class of repulsion and rejection?

Certainly.

Admitting this to be true of desire generally, let us suppose a particular class of desires, and out of these we will select hunger and thirst, as they are termed, which are the most obvious of them?

Let us take that class, he said.

The object of one is food, and of the other drink?

Yes.