The fact seems to be that Greek and Italian plastic art followed different lines of development, owing to the difference of dominant ideas in the races, and to the difference of social custom. Religion naturally played a foremost part in the art-evolution of both epochs. The anthropomorphic Greek mythology encouraged sculptors to concentrate their attention upon what Hegel called "the sensuous manifestation of the idea," while Greek habits rendered them familiar with the body frankly exhibited. Mediaeval religion withdrew Italian sculptors and painters from the problems of purely physical form, and obliged them to study the expression of sentiments and aspirations which could only be rendered by emphasising psychical qualities revealed through physiognomy. At the same time, modern habits of life removed the naked body from their ken. We may go further, and observe that the conditions under which Greek art flourished developed what the Germans call "Allgemeinheit," a tendency to generalise, which was inimical to strongly marked facial expression or characterisation. The conditions of Italian art, on the other hand, favoured an opposite tendency--to particularise, to enforce detail, to emphasise the artist's own ideal or the model's quality. When the type of a Greek deity had been fixed, each successive master varied this within the closest limits possible. For centuries the type remained fundamentally unaltered, undergoing subtle transformations, due partly to the artist's temperament, and partly to changes in the temper of society. Consequently those aspects of the human form which are capable of most successful generalisation, the body and the limbs, exerted a kind of conventional tyranny over Greek art. And Greek artists applied to the face the same rules of generalisation which were applicable to the body.