[WT Sharpe]

Wikipedia says,

Commentators have suggested that nearly every great Greek philosopher can be found within the painting, but determining which are depicted is difficult, since Raphael made no designations outside possible likenesses, and no contemporary documents to explain the painting. Compounding the problem, Raphael had to invent a system of iconography to allude to various figures for whom there were no traditional visual types. For example, while the Socrates figure is immediately recognizable from Classical busts, the alleged Epicurus is far removed from the standard type for that philosopher. Aside from the identities of the figures depicted, many aspects of the fresco have been variously interpreted, but few such interpretations are generally accepted among scholars. The popular idea that the rhetorical gestures of Plato and Aristotle are kinds of pointing (to the heavens, and down to earth) is a likely reading. However Plato’s Timaeus – which is the book Raphael places in his hand – was a sophisticated treatment of space, time and change, including the Earth, which guided mathematical sciences for over a millennium. Aristotle, with his four elements theory, held that all change on Earth was owing to the motions of the heavens. In the painting Aristotle carries his Ethics, which he denied could be reduced to a mathematical science. It is not established how much the young Raphael knew of ancient philosophy, what guidance he might have had from people such as Bramante, or whether a detailed program was dictated by his sponsor, Pope Julius II. Nevertheless the fresco was even recently interpreted as an exhortation to philosophy and, in a deeper way, as a visual representation of the role of Love in elevating people toward upper knowledge, largely in debt with the contemporary theories of Marsilio Ficino and other neo-platonic thinkers linked to Raphael.