1 Numbers in parentheses in text refer to pages in ME or OHE, as the case may be. ME = The Methods of Ethics, 7 th edn., London, 1907; OHE = Outlines of the History of Ethics, 6 th edn., London, 1931.
2 Actually, an intuitionist in Sidgwick's sense might accept IT, though he is not likely to. For he can hold that what is right is not determined in whole or even in part by a consideration of what is good or of what is conducive to an end (ME, p. 3; OHE, p. 6). Even if he holds that there is an end to be pursued, viz., to do the right or to be morally good, he will not use this end in determining what is right or morally good. Thus, he can accept IT as part of the truth but will deny that it is the whole truth or even that it is an important element in the truth.
3 One cannot help but wonder if ‘Once a tautology, always a tautology’ is not necessarily true, but I shall ignore this question.
4 Even if they did regard IT as a tautology, it does not follow that they did not define ‘good’ as Sidgwick says we moderns do. See below.
5 Our footnote first appears in the [left blank] edition. [Guest editor's note: the footnote makes its first appearance in the third edition, of 1884. Also, Sidgwick did not actually see the sixth edition through, before his death.]
6 See his Five Types of Ethical Theory, London, 1930, p. 176. I mistakenly followed Broad in my article on Sidgwick, in Encyclopedia of Morals, ed. Ferm, V., New York, 1956, p. 541.
7 In connection with my discussion, see Schneewind's, J. B.Sidgwick's Ethics and Victorian Moral Philosophy, Oxford, 1977, pp. 221–9. I am much indebted to what he says here. The whole book is excellent as history and as moral philosophy.
8 Here see my ‘Concepts of Rational Action in the History of Ethics’, Social Theory and Practice, ix (1983). Actually, Sidgwick regarded all three of the principles mentioned in the next paragraph as synthetic though necessary.
9 Here see again note 2, above.
10 In connection with this section, see ME, pp. 25, 119; also Schneewind, p. 228, and my ‘Sidgwick and the Dualism of Practical Reason’, Monist, lviii (1974), as well as my ‘Sidgwick and the History of Ethical Dualism’, in Essays on Henry Sidgwick, ed. Schultz, B., New York, 1992. [Guest editor's note: the foregoing article was sent to me by the author around the time that he was working on his contribution for my Essays on Henry Sidgwick; I am delighted to see it appear in this new collection, and like to think that the author would have been pleased with this venue as well. My thanks to Jerry Schneewind, Rob Shaver, Stephen Darwall, and Roger Crisp for confirming that it should be published. For a wonderful memorial tribute to Frankena and his work, see Darwall, Stephen, ‘Learning from Frankena’, Ethics cvii (1997).]