about intuitive, i.e. non-inferential, knowledge of moral principles, which are self-evident to the knower. The criteria for this type of knowledge include that they are expressed in clear terms, that the different principles are mutually consistent with each other and that there is expert consensus on them. According to Sidgwick, commonsense moral principles fail to pass this test, but there are some more abstract principles that pass it, like that "what is right for me must be right for all persons in precisely similar circumstances" or that "one should be equally concerned with all temporal parts of one’s life". The most general principles arrived at this way are all compatible with utilitarianism, which is why Sidgwick sees a harmony between intuitionism and utilitarianism. There are also less general intuitive principles, like the duty to keep one's promises or to be just, but these principles are not universal and there are cases where different duties stand in conflict with each other. Sidgwick suggests that we resolve such conflicts in a utilitarian fashion by considering the consequences of the conflicting actions. Inspired by Sidgwick, 20th century philosopher C.D. Broad would coin the term "deontological ethics" to refer to the normative doctrines associated with intuitionism, leaving the phrase "ethical intuitionism" free to refer to the epistemological doctrines. Intuitionism in analytic philosophy Ethical intuitionism was popular in the early twentieth century, particularly among British analytic philosophers. H.A. Prichard gave a defense of the view in his "Does Moral Philosophy Rest on a Mistake?" (1912), wherein he contended that moral philosophy rested chiefly on the desire to provide arguments starting from non-normative premises for the principles of obligation that we pre-philosophically accept, such as the principle that one ought to keep one's promises or that one ought not to steal. This is a mistake, Prichard argued, both because it is impossible to derive any statement about what one ought to do from statements not concerning obligation (even statements about what is good), and because there is no need to do so since common sense principles of moral obligation are self-evident. Prichard was influenced by G.E. Moore, whose Principia Ethica (1903) argued famously that goodness was an indefinable, non-natural property of which we had intuitive awareness. Moore originated the term "the naturalistic fallacy" to refer to the (alleged) error of confusing goodness with some natural property, and he deployed the Open Question Argument to show why