One of the paradoxical signs that god does not exist is how religious apologists keep trying to prove that s/he does exist. After all, no one tries to prove that the Earth exists or that the Sun exists. Surely the existence of gods should be at least as manifest. As I wrote before, attempts to prove god’s existence may actually weaken belief. But we periodically encounter people who claim that they have a killer argument in support of god’s existence and an exuberant press release touts a new book by Edward Feser that once again claims to do so.
Feser gives an ambitious and complete a defense of traditional natural theology as is currently in print, aiming to vindicate the view of the greatest philosophers of the past — thinkers like Aristotle, Plotinus, Augustine, Aquinas, Leibniz and many others — that the existence of God can be established with certainty by way of purely rational arguments. The FIVE PROOFS OF THE EXISTENCE OF GOD thereby serves as a refutation both of atheism and of the fideism that gives aid and comfort to atheism.
As wags have suggested before, you would not need five arguments for god’s existence if any one of them were really good. Although I have not read this book, I am slightly familiar with Feser’s work and discussed six years ago an article he wrote about what it takes to be a Christian and why all the other religions are wrong. There too he disdained the need for any evidence and said that purely rational arguments are sufficient. I have not read his new book and so can only guess at these proofs but going by the names that are dropped I can guess that they consist of warmed over versions of the prime mover, Kalam, design, and the ontological arguments.
David Hume back in 1779 dismissed the idea that one could prove the existence of a god using rational arguments alonr in his Dialogues Concerning Natural Religion (published posthumously and quoted at D, 9.5/189; cp, EU,12.28–34/ 164–5, retrieved at http://plato.stanford.edu/entries/hume-religion/#WasHumAth) saying:
[T]here is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by arguments a priori. Nothing is demonstrable, unless the contrary is a contradiction. Nothing, that is directly conceivable, implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no Being whose contradiction is demonstrable. (Hume (1779), my italics)
As my own book will argue, the whole idea of ‘proof’ in the mathematical sense has no place when it comes to establishing empirical facts such as the existence of entities.