Professor Gendler reviews four instances of intrapersonal divisions that have appeared in philosophy, literature, psychology, and neuroscience: Plato's division between reason, spirit, and appetite; Hume's division between reason and passion; Freud's division between id, ego, and superego; and four divisions discussed by Jonathan Haidt (mind/body, left brain/right brain, old brain/new brain, and controlled/automatic thought). A discussion of a particularly vivid passage from Plato's phaedrus concludes the lectureEducação Superior::Ciências Humanas::Filosofia