Aquinas' Fifth Way

In the first way, Aquinas denies that there could be an infinite regress of move movers by pointing out that things which have the actuality of motion are non-essential. In the second and third ways, he gets the prime mover in the first way,. A primary cause in the second and so on. And this is what's known as a per se order to causal series. No sorts of causal series they appear in every one of the ways. So you have a per se source of motion or causality in the first and second way, you have aper se source of finality or goodness in the fifth way.