which is an effect of … on and on. This chain of cause and effect can go back for a very long time, but it is not infinite. It must have a definite beginning, according to the cosmological argument, in a First Cause that itself was not caused—an Unmoved Mover, as Aristotle called it. Some argue that this first cause is God. A variation of the cosmological argument is the Kalām argument, which argues from the fact that the universe had a definite beginning, so there must have been something that caused