A (rough) restated formulation of Saint Thomas Aquinas’s second way:

1. There is at least one item X such that X is caused for its existence
2. If (1), then there is at least one cause C of X’s existence
3. If (2), then there is a C such that C either is uncaused, is the last member of a finite causal series, or is the last member of an infinite causal series.
4. It is impossible that there is a C such that C is the last member of an infinite causal series
5. Therefore there is a C such that C is either uncaused or is the last member of a finite causal series
6. For every finite causal series, there is some member F which is uncaused
7. Therefore there is a C such that C is either uncaused or is the last member of a finite causal series for which there is some F which is uncaused
8. Therefore there is either some uncaused C or some uncaused F
9. Therefore, whether C or F, there is something uncaused

Et hoc omnes Deum nominant