Mill, then, has nothing better to say for himself than this. His two fundamental propositions are, in his own words, that to think of an object as desirable (unless for the sake of its consequences), and to think of it as pleasant, are one and the same thing; and that desire anything except in proportion as the idea of it is pleasant, is a physical and metaphysical impossibility. Both of these statements are, we have seen, merely supported by fallacies. The first seems to rest on the naturalistic fallacy; the second rests partly on this, partly on the fallacy of confusing ends and means, and partly on the fallacy of confusing a pleasant thought with the thought of a pleasure. His very language shews this. For that the idea of a thing is pleasant, in his second clause, is obviously meant to be the same fact which he denotes by thinking of it as pleasant, in his first. (§ 44 ¶ 1)

Accordingly, Mill’s arguments for the proposition that pleasure is the sole good, and our refutation of those arguments, may be summed up as follows: (§ 44 ¶ 2)

First of all, he takes the desirable, which he uses as a synonym for the good, to mean what can be desired. The test, again, of what can be desired, is, according to him, what actually is desired: if, therefore, he says, we can find some one thing which is always and alone desired, that thing will necessarily be the only thing that is desirable, the only thing that is good as an end. In this argument the naturalistic fallacy is plainly involved. That fallacy, I explained, consists in the contention that good means nothing but some simple or complex notion, that can be defined in terms of natural qualities. In Mill’s case, good is thus supposed to mean simply what is desired; and what is desired is something which can thus be defined in natural terms. Mill tells us that we ought to desire something (an ethical proposition), because we actually do desire it; but if his contention that I ought to desire means nothing but I do desire were true, then he is only entitled to say, We do desire so and so, because we do desire it; and that is not an ethical proposition at all; it is a mere tautology. The whole object of Mill’s book is to help us to discover what we ought to do; but in fact, by attempting to define the meaning of this ought, he has completely debarred himself from ever fulfilling that object: he has confined himself to telling us what we do do. (§ 44 ¶ 3)

Mill’s first argument then is that, because good means desired, therefore the desired is good; but having thus arrived at an ethical conclusion, by denying that any ethical conclusion is possible, he still needs another argument to make his conclusion a basis for Hedonism. He has to prove that we always do desire pleasure or freedom from pain, and that we never desire anything else whatever. This second doctrine, which Professor Sidgwick has called Psychological Hedonism, I accordingly discussed. I pointed out how obviously untrue it is that we never desire anything but pleasure; and how there is not a shadow of ground for saying even that, whenever we desire anything, we always desire pleasure as well as that thing. I attributed the obstinate belief in these untruths partly to a confusion between the cause of desire and the object of desire. It may, I said, be true that desire can never occur unless it be preceded by some actual pleasure; but even if this is true, it obviously gives no ground for saying that the object of desire is always some future pleasure. By the object of desire is meant that, of which the idea causes desire in us; it is some pleasure, which we anticipate, some pleasure which we have not got, which is the object of desire, whenever we do desire pleasure. And any actual pleasure, which may be excited by the idea of this anticipated pleasure, is obviously not the same pleasure as that anticipated pleasure, of which only the idea is actual. This actual pleasure is not what we want; what we want is always something which we have not got; and to say that pleasure always causes us to want is quite a different thing from saying that what we want is always pleasure. (§ 44 ¶ 4)

Finally, we saw, Mill admits all this. He insists that we do actually desire other things than pleasure, and yet he says we do really desire nothing else. He tries to explain away this contradiction, by confusing together two notions, which he has before carefully distinguished—the notions of means and of end. He now says that a means to an end is the same thing as a part of that end. To this last fallacy special attention should be given, as our ultimate decision with regard to Hedonism will largely turn upon it. (§ 44 ¶ 5)