Mary Elizabeth Podles walks us through the characters and meaning of Raphael’s brilliant fresco, giving it a theological gloss:
Plato points to heaven; Aristotle points to earth. Plato’s drapery swirls around him on the diagonal; Aristotle wears the colors of earth and water, and his folds fall in a much more orderly pattern of horizontals and verticals. Plato is old; Aristotle is a man in his prime. Plato stands almost on tiptoe; Aristotle is firmly planted on the ground, perfectly balanced but, like a Classical statue, full of potential movement. Plato’s followers are young and passionate; Aristotle’s are older and more sharply contoured, more precise.
So the poetical and heavenly strain of Platonic discourse is balanced by the lucid clarity of Aristotelian investigation. But still, they are linked, the two streams merge:
Plato, whose main concern was ethics, holds a discourse on nature, and Aristotle, whose main interest was the natural world, holds his treatise on ethics. They stand in an archway in a colossal, unfinished building: is this overarching architecture a portrait of the new St. Peter’s rising next door?
The School of Athens is on the opposite wall from the Disputa, and so would have been read as the other side of the dialectic: Classical philosophy, the highest manifestation of the natural religions on one side, and Christian theology on the other. If the Disputa is the apse of a basilica, is this picture not the nave, so that the philosophy of the ancients becomes the path that leads to the altar where philosophers and theologians meet, where all human thinking finds fulfillment?
You can see a close-up of the work, including labels for all the key figures depicted, here.