Mystery
I'd say I am quite unsure, I am not that great in Art, but with my small remembrance of what I did in History stduying the Renaissance, I do believe the "Birth of Venus" may of played a birth in the role of beauty, physically. In physically, I mean the art of beauty of the naked perfect body such as the Ancient Greeks and Romans thought of, they built statues of excellent bodies - physical beauty. EDIT: Forgot to add, the backgroudn info, that after the sack of the Roman Empire, culture was barbaric - thus physical beauty was shunned till the renaissance. A "rebirth".