A conjunction of social and aesthetic concerns may account for the rarity of female nudes in the earlier periods of Greek art, as well as the particular form they took when they eventually appeared in the fourth century. Few civilized societies have been so completely male-dominated as that of ancient Greece. Laws make this abundantly clear: adultery, for example, was defined one-sidedly as intercourse between a married woman and a man who was not her husband, rape as an offence against a woman’s husband, father or guardian, not herself. Regarded and guarded as possessions, upper-class wives were kept at home and confined to childrearing and household maintenance, while their husbands sought emotional, physical and intellectual stimulus elsewhere, either with members of their own sex or among the hetairai or porne (common prostitutes). The latter were depicted naked, in a variety of seductive poses, on sixth and fifth-century vases, usually in brothel scenes, which are pornographic in the strictest meaning of the word. To have included a nude female among the statues of male athletes which crowded the sanctuaries would therefore have seemed extremely odd.
Hugh Honour and John Fleming, The Visual Arts: A History, 2002