Philosophers of religion as a part of their discipline, sometimes engage in the formulation and defense of arguments for the existence of God. We are aware of this.
However, it is oftentimes forgotten that they also interact with arguments against theism. In this thread, we will discuss those which atheists here think are most persuasive.
Any takers?
A Philpapers.org survey conducted in 2009 would suggest that a strong majority of professional philosophers are atheists, or at least inclined to non-theism:
God: theism or atheism?
Accept or lean toward: atheism 1257 / 1803 (69.7%)
Accept or lean toward: theism 295 / 1803 (16.4%)
Other 251 / 1803 (13.9%)
(As an aside: the only two other topics that philosophers leant towards as strongly were scientific realism (70.1%) and non-skeptical realism (76.7%) - i.e that we actually do live in the world we perceive and we can use the scientific method to discover truths about that real world._
The question we might then ask is: why aren't philosophers more active in formulating arguments against the existence of God?
I think that the answer to this question lies in the mindset of philosophers. As the majority of them clearly don't believe in a God or gods, they have little or no reason to discuss the topic. Atheism is not a positive claim in and of it self. Atheism is the non-acceptance of a claim of other. Thus, there is little for professional philosophers to debate a non-positivist position, and thus little reason for them to formulate arguments for the non-existence of God and/or gods.
Or maybe they think that its something that has already been addressed and they don't need to do it.
As for me, I find two main defeaters of the classical Christian God, which I will define as the God of the Bible with the properties of omniscience, omnipotence, omnibenevolence and omnipresence which chooses to interact with physical reality in some way.
The first is that the god of the omnis is logically incoherent, in that its properties are ultimately logically self-contradicting. Some apologists get around this by exchanging omniXXXXX for 'maximally', but this is just a linguistic evasion.
The second is the problem of divine hidden-ness. I'm not going to launch into a full formulation, as there are a couple of excellent philosophical videos from two of my favourite non-believers, Matt Dillahunty (28-ish minute video) and Scott Clifton (10-ish minute video):