Letters 91.17

Alexander, king of Macedon, began to study geometry; unhappy man, because he would thereby learn how puny was that earth of which he had seized but a fraction! Unhappy man, I repeat, because he was bound to understand that he was bearing a false title. For who can be “great” in that which is puny? The lessons which were being taught him were intricate and could be learned only by assiduous application; they were not the kind to be comprehended by a madman, who let his thoughts range beyond the ocean. “Teach me something easy!” he cries; but his teacher answers: “These things are the same for all, as hard for one as for another.”

Seneca, Letters to Lucilius 91.17, translated by Richard Mott Gummere