Timaeus & Critias is a Socratic dialogue in two parts A response to an account of an ideal state told by Socrates it begins with Timaeus's theoretical exposition of the cosmos & his story describing the creation of the universe from its very beginning to the coming of man Timaeus introduces the idea of a creator God & speculates on the structure & composition of the physical world Critias the second part of Plato's dialogue comprises an account of the rise & fall of Atlantis an ancient mighty & prosperous empire ruled by the descendents of Poseidon which ultimately sank into the sea