The Third Way: Argument from Possibility and Necessity (Reductio argument)
We find in nature things that are possible to be and not to be, that come into being and go out of being i.e., contingent beings.
Assume that every being is a contingent being.
For each contingent being, there is a...
The Second Way: Argument from Efficient Causes
We perceive a series of efficient causes of things in the world.
Nothing exists prior to itself.
Therefore nothing [in the world of things we perceive] is the efficient cause of itself.
If a previous efficient cause does not exist, neither...