This economic factor necessarily involved the introduction of a new moral element into modesty. If a woman's chastity is the property of another person, it is essential that she shall be modest in order that men may not be tempted to incur the penalties involved by the infringement of property rights. Thus modesty is strictly inculcated on women in order that men may be safeguarded from temptation. The fact was overlooked that modesty is itself a temptation. Immodesty being, on this ground, disapproved by men, a new motive for modesty is furnished to women. In the book which the Knight of the Tower, Landry, wrote in the fourteenth century, for the instruction of his daughters, this factor of modesty is naïvely revealed. He tells his daughters of the trouble that David got into through the thoughtlessness of Bathsheba, and warns them that "every woman ought religiously to conceal herself when dressing and washing, and neither out of vanity nor yet to attract attention show either her hair, or her neck, or her breast, or any part which ought to be covered." Hinton went so far as to regard what he termed "body modesty," as entirely a custom imposed upon women by men with the object of preserving their own virtue. While this motive is far from being the sole source of modesty, it must certainly be borne in mind as an inevitable outcome of the economic factor of modesty. In Europe it seems probable that the generally accepted conceptions of mediæval chivalry were not without influence in constituting the forms in which modesty shows itself among us. In the early middle ages there seems to have been a much greater degree of physical familiarity between the sexes than is commonly found among barbarians elsewhere. There was certainly considerable promiscuity in bathing and indifference to nakedness. It seems probable, as Durkheim points out,[56] that this state of things was modified in part by the growing force of the dictates of Christian morality, which regarded all intimate approaches between the sexes as sinful, and in part by the influence of chivalry with its æsthetic and moral ideals of women, as the representative of all the delicacies and elegancies of civilization. This ideal was regarded as incompatible with the familiarities of the existing social relationships between the sexes, and thus a separation, which at first existed only in art and literature, began by a curious reaction to exert an influence on real life.