Plato was both a great philosopher and a great poet. His philosophical system is at the same time an enchanting vision. Metaphor and symbol and sometimes calculated myth substitute for elaboration of details. In a period in which scientific details were not yet available, that was of undoubted use. One can always fill the symbolic margin with more up-to-date details. Aristotle, Plato's student, had the mind of a writer of prose. Thought does not have to be nicely phrased, but it should be as clear as possible. Not literary dialogs but lecture notes are the correct "literary genre" of philosophical inquiry.