12 “Ce que les hommes ont nommé amitié n’est qu’une société, qu’un ménagement réciproque d’intérêts et qu’un échange de bons offices. Ce n’est enfin qu’un commerce où l’amour-propre se propose toujours quelque chose à gagner.”—La Rochefoucauld, _Max._ 83. See this idea developed at large in Helvétius. 13 “La science de la morale n’est autre chose que la science même de la législation.”—Helvétius _De l’Esprit_, ii. 17. 14 This doctrine is expounded at length in all the moral works of Hobbes and his school. The following passage is a fair specimen of their meaning:—“Moral philosophy is nothing else but the science of what is good and evil in the conversation and society of mankind. Good and evil are names that signify our appetites and aversions, which in different tempers, customs, and doctrines of men are different ... from whence arise disputes, controversies, and at last war. And therefore, so long as man is in this condition of mere nature (which is a condition of war), his private appetite is the measure of good and evil. And consequently all men agree in this, that peace is good, and therefore also that the ways or means of peace, (which, as I have showed before) are justice, gratitude, modesty, equity, mercy, and the rest of the laws of nature are good ... and their contrary vices evil.”—Hobbes’ _Leviathan_, part i. ch. xvi. See, too, a striking passage in Bentham’s _Deontology_, vol. ii. p. 132. 15 As an ingenious writer in the _Saturday Review_ (Aug. 10, 1867) expresses it: “Chastity is merely a social law created to encourage the alliances that most promote the permanent welfare of the race, and to maintain woman in a social position which it is thought advisable she should hold.” See, too, on this view, Hume’s _Inquiry concerning Morals_, § 4, and also _note_ x.: “To what other purpose do all the ideas of chastity and modesty serve? Nisi utile est quod facimus, frustra est gloria.”