Head of PlatoThis marble head of the philosopher is a later Roman copy of one made in the fourth century B.C.E. by the Greek sculptor Silanion, which had apparently been installed in the Academy of Athens shortly after Plato’s death. Idealized portraits in marble of writers, thinkers, rulers, and statesmen became a popular art form in the later classical period and shaped all later depictions of these individuals. (Erin Babnik/Alamy)