Plato and Aristotle! These are not merely two systems, they are types of two distinct human natures, which from time immemorial, under every sort of disguise, stand more or less inimically opposed. The whole medieval world in particular was riven by this conflict, which persists down to the present day, and which forms the most essential content of the history of the Christian Church. Although under other names, it is always of Plato and Aristotle that we speak. Visionary, mystical, Platonic natures disclose Christian ideas and the corresponding symbols from the fathomless depths of their souls. Practical, orderly, Aristotelian natures build out of these ideas and symbols a fixed system, a dogma and a cult. Finally the Church embraces both natures, one of them entrenched in the clergy and the other in monasticism, but both keeping up a constant feud.

—Heine, Deutschland, I