“Does Moral Philosophy Rest upon a Mistake?” is the name of the 1912 paper by H. A. Prichard. Moral philosophy has assumed the task of providing a justification for holding a certain kind of view of man’s duty. In his paper Prichard tries to prove that the demand for such a reason or justification is untenable. To defend his position, he makes two arguments. His first argument is that people may try to justify the view that something is their duty by showing that what is their duty is essential to their pleasure, or conducive for some good, but if pleasure and some good are the ultimate goals then people are not treating whatever they assume to be their duty as their duty. In his second argument, Prichard appeals to the things of which we are supposed to be conscious and notes that since the apprehension of duty is automatic, it cannot be supported by reason and what is not supported by reason must be amoral.