The Argument from Time and Contingency

1. We notice around us things that come into being and go out of being. A tree, for example, grows from a tiny shoot, flowers brilliantly, then withers and dies.
2. Whatever comes into being or goes out of being does not have to be; non-being is a real possibility.
3. Suppose that nothing has to be; that is, that non-being is a real possibility for everything.
4. Then right now nothing would exist. Since...
5. If the universe began to exist, then all being must trace its origin to some past moment before which there existed—literally—nothing at all. But...
6. From nothing nothing comes. So...
7. The universe could not have begun.
8. But suppose the universe never began. Then, for the infinitely long duration of cosmic history, all being had the built-in possibility not to be. But...
9. If in an infinite time that possibility was never realized, then it could not have been a real possibility at all. So...
10. There must exist something which has to exist, which cannot not exist. This sort of being is called necessary.
11. Either this necessity belongs to the thing in itself or it is derived from another. If derived from another there must ultimately exist a being whose necessity is not derived, that is, an absolutely necessary being.
12. This absolutely necessary being is God.