BOOK IV. · 11

Let us take that class, he said.

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

Yes.

And here comes the point: is not thirst the desire which the soul has of drink, and of drink only; not of drink qualified by anything else; for example, warm or cold, or much or little, or, in a word, drink of any particular sort: but if the thirst be accompanied by heat, then the desire is of cold drink; or, if accompanied by cold, then of warm drink; or, if the thirst be excessive, then the drink which is desired will be excessive; or, if not great, the quantity of drink will also be small: but thirst pure and simple will desire drink pure and simple, which is the natural satisfaction of thirst, as food is of hunger?

Yes, he said; the simple desire is, as you say, in every case of the simple object, and the qualified desire of the qualified object.

But here a confusion may arise; and I should wish to guard against an opponent starting up and saying that no man desires drink only, but good drink, or food only, but good food; for good is the universal object of desire, and thirst being a desire, will necessarily be thirst after good drink; and the same is true of every other desire.

Yes, he replied, the opponent might have something to say.

Nevertheless I should still maintain, that of relatives some have a quality attached to either term of the relation; others are simple and have their correlatives simple.

I do not know what you mean.

Well, you know of course that the greater is relative to the less?

Certainly.

And the much greater to the much less?

Yes.

And the sometime greater to the 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?