sometime less, and the greater that is
to be to the less that is to be?

Certainly, he said.

And so of more and less, and of other correlative terms, such as the
double and the half, or again, the heavier and the lighter, the swifter
and the slower; and of hot and cold, and of any other relatives;--is
not this true of all of them?

Yes.

And does not the same principle hold in the sciences? The object of
science is knowledge (assuming that to be the true definition), but the
object of a particular science is a particular kind of knowledge; I
mean, for example, that the science of house-building is a kind of
knowledge which is defined and distinguished from other kinds and is
therefore termed architecture.

Certainly.

Because it has a particular quality which no other has?

Yes.

And it has this particular quality because it has an object of a
particular kind; and this is true of the other arts and sciences?

Yes.

Now, then, if I have made myself clear, you will understand my original
meaning in what I said about relatives. My meaning was, that if one
term of a relation is taken alone, the other is taken alone; if one
term is qualified, the other is also qualified. I do not mean to say
that relatives may not be disparate, or that the science of health is
healthy, or of disease necessarily diseased, or that the sciences of
good and evil are therefore good and evil; but only that, when the term
science is no longer used absolutely, but has a qualified object which
in this case is the nature of health and disease, it becomes defined,
and is hence called not merely science, but the science of medicine.

I quite understand, and I think as you do.

Would you not say that thirst is one of these essentially relative
terms, having clearly a relation--

Yes, thirst is relative to drink.

And a certain kind of thirst is relative to a certain kind of drink;
but thirst taken alone is neither of much nor little, nor of good nor
bad, nor of any particular kind of drink, but of drink only?

Certainly.

Then the soul of the thirsty one, in so far as he is thirsty, desires
only drink; for this he yearns and tries to obtain it?

That is plain.

And if you suppose something which pulls a thirsty soul away from
drink, that must be different from the thirsty principle which draws
him like a beast to drink; for, as we were saying, the same thing
cannot at the same time with the same part of itself act in contrar