 [T]he fundamental principles of Ethics must be self-evident. But I am anxious that this expression should not be misunderstood. The expression “self-evident” means properly that the proposition so called is evident or true, by itself alone; that it is not an inference from some proposition other than itself. The expression does not mean that the proposition is true, because it is evident to you or me or all mankind, because in other words it appears to us to be true. That a proposition appears to be true can never be a valid argument that true it really is. By saying that a proposition is self-evident, we mean emphatically that its appearing so to us, is not the reason why it is true: for we mean that it has absolutely no reason. It would not be a self-evident proposition, if we could say of it: I cannot think otherwise and therefore it is true. For then its evidence or proof would not lie in itself, but in something else, namely our conviction of it. That it appears true to us may indeed be the cause of our asserting it, or the reason why we think and say that it is true: but a reason in this sense is something utterly different from a logical reason, or reason why something is true. Moreover, it is obviously not a reason of the same thing. The evidence of a proposition to us is only a reason for our holding it to be true; whereas a logical reason, or reason in the sense in which self-evident propositions have no reason, is a reason why the proposition itself must be true, not why we hold it so to be. Again, that a proposition is evident to us may not only be the reason why we do think or affirm it, it may even be a reason why we ought to think it or affirm it. But a reason, in this sense too, is not a logical reason for the truth of the proposition, though it is a logical reason for the rightness of holding the proposition…. When, therefore, I talk of Intuitionistic Hedonism, I must not be understood to imply that my denial that “Pleasure is the only good” is based on my Intuition of its falsehood. My Intuition of its falsehood is indeed my reason for holding and declaring it untrue; it is indeed the only valid reason for so doing. But that is just because there is no logical reason for it; because there is no proper evidence or reason of its falsehood except for itself alone. It is untrue, because it is untrue, and there is no other reason: but I declare it untrue, because its untruth is evident to me, and I hold that that is a sufficient reason for my assertion. We must not therefore look on Intuition, as if it were an alternative to reasoning. Nothing whatever can take the place of reasons for the truth of any proposition: intuition can only furnish a reason for holding any proposition to be true: this however it must do when any proposition is self-evident, when, in fact, there are no reasons which prove its truth. (1903 [2003]: 143–144)