"Plotinus devoted himself to the methodical task of transforming the direction of studies so that it corresponded to the greatness of the empire and its current problems. To this end, he started again from Plato and the interpretation of Plato; instead, he proposed Aristotle and his method as a subject of study and discussion. When Gallienus, who had recognised him as Caesar, rose to supreme power, he also had the authority and character of official teacher of the empire's philosophy. ('La vita e l'opera di Plotino, “'The Life and Work of Plotinus”', V, p. 37)"