five ways...

1. Motion: Some things undoubtedly move, though cannot cause their own motion. Since, as Thomas believed, there can be no infinite chain of causes of motion, there must be a First Mover not moved by anything else, and this is what everyone understands by God.
2. Causation: As in the case of motion, nothing can cause itself, and an infinite chain of causation is impossible, so there must be a First Cause, called God.
3. Existence of necessary and the unnecessary: Our experience includes things certainly existing but apparently unnecessary. Not everything can be unnecessary, for then once there was nothing and there would still be nothing. Therefore, we are compelled to suppose something that exists necessarily, having this necessity only from itself; in fact itself the cause for other things to exist.
4. Gradation: If we can notice a gradation in things in the sense that some things are more hot, good, etc., there must be a superlative that is the truest and noblest thing, and so most fully existing. This then, we call God.
5. Ordered tendencies of nature: A direction of actions to an end is noticed in all bodies following natural laws. Anything without awareness tends to a goal under the guidance of one who is aware. This we call God.^[130]