  Reinach next surveys Hume, who familiarly provides an account of why a promise is binding which rests on the idea that there is a certain sort of sui generis experience which becomes expressed in a promise and which is somehow binding on the subject but which is at the same time analogous to experiences of resolving, wishing, willing in that it can be present also without any accompanying expression. Reinach rejects this account – denying that such an experience could exist – and rejects also a variety of other psychologistic and consequentialistic theories because they are, he claims, seeking an explanation of a phenomenon so basic that it cannot be further elucidated in terms of anything more simple. As he himself expresses it: