First Way MOTION
- Based on motion, including movement from 1 place to another/ in the sense of change.
- When something is put in motion, a change takes place.
- There must be something which sets things in motion - 'Unmoved mover.'
- Aq explained the need for an external influence. E.g. an object moves when an external force is applied to it.
- This chain of movement cannot go back to infinity.
- There must be a first unmoved mover that began the movement in everything else without itself being moved - God.
- Aq showed how things achieve their potential through an external influence.
- Change requires actuality. E.g. the fact that wood is wood = actuality, the fact that fire can make it hot = potentiality.
- Something must have caused the fire to change and become alight.
- Therefore, each change is the result of a previous change.
- God is the actuality but he does not have potentiality bc that would mean he isn't God.
- Aq rejected an infinite series of changes bc he believed that the point when the first movement occurred was brought about by Unmoved Mover.
- This is God.
Second Way CAUSE
- Based on cause
- Aq identified a series of causes and effects in O.
- Nothing could be the cause of itself bc that would mean it had to exist before it existed which is a logical impossibility.
- Without cause, there would be no other effects.
- Aq rejected an infinite series of causes bc that would mean there is no first mover.
- He rejected the idea of an infinite regression of movers putting nothing into motion.
- There was a first uncaused cause that caused all other events to happen - God.
- Aq did not think that cause went back to infinity.
- To deny infinite regress means that he believed in an eternal being that was not dependant on anything else for its existence.
- Uncaused cause is God.
Third Way CONTINGENCY
- Based on contingency.
- Something must have started off the O bc everything that exists in the O has a cause.
- O began to exist, therefore O must have a cause.
- Aq examined all contingent matter and the possibility of infinite time.
- If time is infinite then there must have been a time when nothing existed bc of contingency. Everything in the O is contingent which means it cannot go on forever.
- If there was nothing then there would still be nothing as nothing can bring itself into existence.
- Cause of O = eternal and has always existed.
- Aq called this the 'necessary being' - God.
- Everything in the universe has a finite conditional existence whose existence depends on an infinite unconditional cause - God.
- Every cause in the chain of causes is dependant on God for its existence.
- God = Necessary being who upholds the existence of everything.
Seeks to prove the existence of God based on the fact that there is a universe.
Cosmos = universe (O).
Developed from Aristotle's view of God as sustaining the universe
..... by Thomas Aquinas in his 'Summa Theologica' in which he devised 5 ways to prove the existence of God, the first 3 being:
It is an a posteriori argument bc it is based on what can be seen and observed.