A central question in Western philosophy is whether the universe was created or is eternal. The question has profound ramifications for whether reality is absolute or depends on something else such as God (i.e., what Ayn Rand called the primacy of existence or of consciousness). This talk examines how and why Plato and Aristotle developed the two basic positions, creationism and eternalism, respectively, and how their arguments are still crucially relevant to contemporary philosophy and science.