“Man's secret horror of his foot is one of the explanations for the tendency to conceal its length and form as much as possible. Heels of greater or lesser height, depending on the sex, distract from the foot's low and flat character. Besides the uneasiness is often confused with a sexual uneasiness; this is especially striking among the Chinese who, after having atrophied the feet of women, situate them at the most excessive point of deviance. The husband himself must not see the nude feet of his wife, and it is incorrect and immoral in general to look at the feet of women. Catholic confessors, adapting themselves to this aberration, ask their Chinese penitents "if they have not looked at women's feet.
The same aberration is found among the Turks (Volga Turks, Turks of Central Asia), who consider it immortal to show their nude feet and whoe ven go to bed in stockings.
Nothing similar can be cited from classical antiquity (apart from the use of very high soles in tragedies). The most prudish Roman matrons constantly allowed their nude toes to be seen. On the other hand, modesty concerning feet developed excessively in the modern ea and only started to disappear in the nineteenth century. M. Salomon Reinarch has studied this development in detail in the article entitled Pieds pudiques [Modest Feet], insisting on the role of Spain, where women's feet have been the object of most dreaded anxiety and thus were the cause of crimes. The simple fact of allowing the shod foot to be seen, jutting up from under a skirt, was regarded as indecent. Under no circumstances was it possible to touch the foot of a woman.”

Source: Visions of Excess: Selected Writings 1927-1939, p.21-22