Published online by Cambridge University Press: 25 February 2009
Was Hume here claiming or implying that propositions about what men ought to do are radically different from purely factual propositions, and that they cannot ever be entailed by any purely factual propositions? No, despite Mr Hare, Professor Nowell-Smith, Professor Ayer, Miss Murdoch, Professor Flew, Mr Basson, and The Observer's Brief Guide to philosophy.
page 149 note 1 Cp. Enquiry concerning the Principles of Morals (S.-B., p. 289): ‘The hypothesis which we embrace is plain. It maintains that morality is determined by sentiment. It defines virtue to be whatever mental action or quality gives to a spectator the pleasing sentiment of approbation; and vice the contrary. We then proceed to examine a plain matter of fact, to wit, what actions have this influence.’
page 150 note 1 The possibility of this interpretation was suggested to me by Professor Ryle.