=36.= In this chapter we have to deal with what is perhaps the most famous and the most widely held of all ethical principles--the principle that nothing is good but pleasure. My chief reason for treating of this principle in this place is, as I said, that Hedonism appears in the main to be a form of Naturalistic Ethics: in other words, that pleasure has been so generally held to be the sole good, is almost entirely due to the fact that it has seemed to be somehow involved in the _definition_ of ‘good’--to be pointed out by the very meaning of the word. If this is so, then the prevalence of Hedonism has been mainly due to what I have called the naturalistic fallacy--the failure to distinguish clearly that unique and indefinable quality which we mean by good. And that it is so, we have very strong evidence in the fact that, of all hedonistic writers, Prof. Sidgwick alone has clearly recognised that by ‘good’ we do mean something unanalysable, and has alone been led thereby to emphasise the fact that, if Hedonism be true, its claims to be so must be rested solely on its self-evidence--that we must maintain ‘Pleasure is the sole good’ to be a mere _intuition_. It appeared to Prof. Sidgwick as a new discovery that what he calls the ‘method’ of Intuitionism must be retained as valid alongside of, and indeed as the foundation of, what he calls the alternative ‘methods’ of Utilitarianism and Egoism. And that it was a new discovery can hardly be doubted. In previous Hedonists we find no clear and consistent recognition of the fact that their fundamental proposition involves the assumption that a certain unique predicate can be directly seen to belong to pleasure alone among existents: they do not emphasise, as they could hardly have failed to have done had they perceived it, how utterly independent of all other truths this truth must be.