is fundamental to Greek philosophy. It is a contrast between what is fundamental, primary, or ultimate and what is dependent and derivative. Timaeus’s question is thus a request for what is ultimate. What we perceive by our senses cannot be described as always being with no becoming. Since the world as a whole is visible and tangible, that is, perceived by the senses, it cannot be fundamental. But what is its cause? Here Timaeus makes a cryptic remark that reverberated powerfully in the Christian