[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 t