Taking upon me once to justify something in use amongst us, and that was received with absolute authority for a great many leagues round about us, and not content, as men commonly do, to establish it only by force of law and example, but inquiring still further into its origin, I found the foundation so weak, that I who made it my business to confirm others, was very near being dissatisfied myself. 'Tis by this receipt that Plato --[Laws, viii. 6.]--undertakes to cure the unnatural and preposterous loves of his time, as one which he esteems of sovereign virtue, namely, that the public opinion condemns them; that the poets, and all other sorts of writers, relate horrible stories of them; a recipe, by virtue of which the most beautiful daughters no more allure their fathers' lust; nor brothers, of the finest shape and fashion, their sisters' desire; the very fables of Thyestes, OEdipus, and Macareus, having with the harmony of their song, infused this wholesome opinion and belief into the tender brains of children. Chastity is, in truth, a great and shining virtue, and of which the utility is sufficiently known; but to treat of it, and to set it off in its true value, according to nature, is as hard as 'tis easy to do so according to custom, laws, and precepts. The fundamental and universal reasons are of very obscure and difficult research, and our masters either lightly pass them over, or not daring so much as to touch them, precipitate themselves into the liberty and protection of custom, there puffing themselves out and triumphing to their heart's content: such as will not suffer themselves to be withdrawn from this original source, do yet commit a greater error, and subject themselves to wild opinions; witness Chrysippus,--[Sextus Empiricus, Pyyrhon. Hypotyp., i. 14.]--who, in so many of his writings, has strewed the little account he made of incestuous conjunctions, committed with how near relations soever.