PROF. H. J. PATON, in his lecture to the British Academy entitled "Can Reason be Practical?" (London: Oxford University Press, 1944. 4s. net), defends against recent attacks the view that moral principles are rules of reason. Some have maintained that moral judgments are merely the expression of private emotions or merely the result of pressure of the social environment, and that the attempt to justify them is 'rationalization' in the bad sense. Against these critics he argues that if they would only apply their theories to their own judgments they would see their absurdity. Those who oppose instinct or intuition to reason are making a false antithesis. The infant sucks by instinct, but ought to realize later that it was the most reasonable thing to do in the circumstances. Prof. Paton develops the positive side of his argument from the starting point that human conduct should at least be intelligent, that is to say, consistent and orderly, so that means are adapted to ends and conflicting impulses subordinated. The principles of practical reason are the result of taking this notion of order and consistency as far as it will go and generalizing as completely as possible. The rest of Prof. Paton's exposition is on Kantian lines, but with some useful clarification and, perhaps, some modification in the direction of what Kant ought to have said.