If the reader wishes to form an impartial judgment as to what the fundamental problems of Ethics really are, and what is the true answer to them, it is of the first importance that he should not confine himself to reading works of any one single type, but should realize what extremely different sorts of things have seemed to different writers, of acknowledged reputation, to be the most important things to be said about the subject.

G. E. Moore, Ethics, London, 1912, p. 253