The first philosopher who taught this was Parmenides, who identified Existence and Intelligence, and who does not place existence among sense-objects, "for, thought is the same thing as existence."[246] He adds[247] that existence is immovable, although being thought. Parmenides thus denies all corporeal movement in existence, so as that it might always remain the same. Further, Parmenides[248] compares existence to a sphere, because it contains everything, drawing thought not from without, but from within itself. When Parmenides, in his writings, mentions the One, he means the cause, as if he recognized that this unity (of the intelligible being) implied manifoldness. In the dialogue of Plato he speaks with greater accuracy, and distinguishes three principles: the First, the absolute One; the second, the manifold one; the third, the one and the manifold. He therefore, as we do, reaches three natures. ANAXAGORAS TEACHES THE SAME THING. 9. Anaxagoras, who teaches a pure and unmingled Intelligence[249] also insists that the first Principle is simple, and that the One is separated from sense-objects. But, as he lived in times too ancient, he has not treated this matter in sufficient detail. HERACLITUS ALSO TAUGHT THE SAME THING. Heraclitus also taught the eternal and intelligible One; for Heraclitus holds that bodies are ceaselessly "becoming" (that is, developing), and that they are in a perpetual state of flux.[250] EMPEDOCLES TAUGHT THE SAME THING. In the system of Empedocles, discord divides, and concord unites; now this second principle is posited as incorporeal, and the elements play the part of matter.[251] ARISTOTLE TAUGHT THE SAME THING.