Coleridge observes that all men are born Aristotelians or Platonists. The latter feel that classes, orders, and genres are realiti es; the former, that they are generalizations. For the latter, language is nothing but an approximative set of symbols; for the former, it is the map of the universe. The Platonist knows that the universe is somehow a cosmos, an order; that order, for the Aristotelian, can be an error or a fiction of our partial knowledge. Across the latitudes and the epochs, the two immortal antagonists change their name and language: one is Parmenides, Plato, Spinoza, Kant, Francis Bradley; the other, Heraclitus, Aristotle, Locke, Hume, William James.