   One thing worthy of note is that these cases test intuitions about our overall moral judgements—that is, about what we should, or may do in certain circumstances. But not all intuitionists claim that principles about what we ought to do are self-evident. W. D. Ross for example claimed that only principles of prima facie duty are self-evident, and principles of prima facie duty are, roughly, principles stating that certain facts count in favour of an act and others count against. So these principles state, for instance, that  the fact that one’s act would produce some good, or the fact that it  would be the keeping of a promise, or the expression of gratitude, etc., counts in favour of it, and the fact that, for example, it would involve the infliction of harm on someone counts against it. What we ought to do is determined by all of these facts, and how they weigh up against each other. Ross denied that we can ever know what we ought to do, and rejected the view that there could be strictly universal, self-evident principles specifying what we ought to do.