A man . . . who exercises his brain alone will probably be ill in consequence: but he may exercise his brain much and his legs little, or vice versa, without any morbid results.
(Henry Sidgwick, The Methods of Ethics, 7th ed. [Indianapolis: Hackett Publishing Company, 1981], bk. II, chap. VI, sec. 4, p. 193 [ellipsis added] [first published in 1907; 1st ed. published in 1874])
Keith Burgess-Jackson, J.D., Ph.D. 