Surely this drawing is among the most precious works of the collection and of the city of Milan. It is the largest Renaissance cartoon that has survived and was executed by Raffaello Sanzio, as a preparation for the fresco in the Stanza della Segnatura in the Vatican, which was painted by Julius II. It became part of Federico Borromeo's collection in 1626, when he bought it from the widow of Fabio Borromeo Visconti for the huge sum of six hundred imperial lire, even though it was actually placed on loan at the Ambrosiana as early as 1610. known as the School of Athens, the most exact title would be La Filosofia, as suggested by the allegory of the same name painted in the sail above the fresco in the Stanza della Segnatura, according to a very complex iconographic project. Recognizable, in the center, are the two greatest philosophers Plato (painted with the likeness of Leonardo, with the finger pointing upwards and recognizable because he is holding the Timaeus, one of his works that greatly influenced subsequent philosophy) and Aristotle, identifiable by book of ethics.