=14.= ‘Good,’ then, is indefinable; and yet, so far as I know, there is only one ethical writer, Prof. Henry Sidgwick, who has clearly recognised and stated this fact. We shall see, indeed, how far many of the most reputed ethical systems fall short of drawing the conclusions which follow from such a recognition. At present I will only quote one instance, which will serve to illustrate the meaning and importance of this principle that ‘good’ is indefinable, or, as Prof. Sidgwick says, an ‘unanalysable notion.’ It is an instance to which Prof. Sidgwick himself refers in a note on the passage, in which he argues that ‘ought’ is unanalysable[2]. [2] _Methods of Ethics_, Bk. I, Chap. iii, § 1 (6th edition). ‘Bentham,’ says Sidgwick, ‘explains that his fundamental principle “states the greatest happiness of all those whose interest is in question as being the right and proper end of human action”’; and yet ‘his language in other passages of the same chapter would seem to imply’ that he _means_ by the word “right” “conducive to the general happiness.” Prof. Sidgwick sees that, if you take these two statements together, you get the absurd result that ‘greatest happiness is the end of human action, which is conducive to the general happiness’; and so absurd does it seem to him to call this result, as Bentham calls it, ‘the fundamental principle of a moral system,’ that he suggests that Bentham cannot have meant it. Yet Prof. Sidgwick himself states elsewhere[3] that Psychological Hedonism is ‘not seldom confounded with Egoistic Hedonism’; and that confusion, as we shall see, rests chiefly on that same fallacy, the naturalistic fallacy, which is implied in Bentham’s statements. Prof. Sidgwick admits therefore that this fallacy is sometimes committed, absurd as it is; and I am inclined to think that Bentham may really have been one of those who committed it. Mill, as we shall see, certainly did commit it. In any case, whether Bentham committed it or not, his doctrine, as above quoted, will serve as a very good illustration of this fallacy, and of the importance of the contrary proposition that good is indefinable. [3] _Methods of Ethics_, Bk. I, Chap. iv, § 1.