When clothing is once established, another element, this time a social-economic element, often comes in to emphasize its importance and increase the anatomical modesty of women. I mean the growth of the conception of women as property. Waitz, followed by Schurtz and Letourneau, has insisted that the jealousy of husbands is the primary origin of clothing, and, indirectly, of modesty. Diderot in the eighteenth century had already given clear expression to the same view. It is undoubtedly true that only married women are among some peoples clothed, the unmarried women, though full grown, remaining naked. In many parts of the world, also, as Mantegazza and others have shown, where the men are naked and the women covered, clothing is regarded as a sort of disgrace, and men can only with difficulty be persuaded to adopt it. Before marriage a woman was often free, and not bound to chastity, and at the same time was often naked; after marriage she was clothed, and no longer free. To the husband's mind, the garment appears--illogically, though naturally--a moral and physical protection against any attack on his property.[53] Thus a new motive was furnished, this time somewhat artificially, for making nakedness, in women at all events, disgraceful. As the conception of property also extended to the father's right over his daughters, and the appreciation of female chastity developed, this motive spread to unmarried as well as married women. A woman on the west coast of Africa must always be chaste because she is first the property of her parents and afterwards of her husband,[54] and even in the seventeenth century of Christendom so able a thinker as Bishop Burnet furnished precisely the same reason for feminine chastity.[55] This conception probably constituted the chief and most persistent element furnished to the complex emotion of modesty by the barbarous stages of human civilization.