Sunday, December 09, 2018

Aquinas' Five "Proofs" for God's Existence?

There's a question about the status of Aquinas' five ways to "prove" God's existence. Are they really proofs after all?

The five ways are:

1) The argument from motion
2) argument from efficient causes
3) argument from possibility and necessity
4) argument from degress of perfection/gradations of being
5) argument from the governance of the world

Concerning these five ways, here's what I once wrote to a colleague:

In Prima Pars, Quest. 2, Articulus 3 of the Summa Thelogiae, Aquinas does write: "Respondeo dicendum quod Deum esse quinque viis probari potest."

But I would agree that reason is limited; a posteriori demonstrations (like the five ways) can only show that God's existence is possible or maybe probable.

For the potential sense of the Latin word, probari, see

Compare the words of Cicero (Ver. 2.1.10): "his ego iudicibus non probabo C. Verrem contra leges pecuniam cepisse?"


David Waltz said...

Hi Edgar,

Are you aware of the following book:

Five Proofs

Grace and peace,


Edgar Foster said...

Thank you, David. I do have that book and would highly recommend it and other works by Feser.