I haven’t read Coyne’s responses to all his critics but I did read the notorious first anti-philosophy blog and one of its follow-ups. Let’s call his argument what it is: silly.
He may have elaborated on it so that it is a better argument but I just can’t see any way to make it sound.
His main argument simply seems to be that we need to think deeply about non existent beings such as god and all philosophical problems related to god. This reasoning seems to suggest that non existent beings are irrelevant to the pursuit of anything worthwhile such as the pursuit of truth.
But that assumption is clearly false. Examples from science, a subject that Coyne should be familiar with shows this falsity. Scientists make use of all sorts of fictional objects (in clear-eyed understanding that they do not existent) in their thought experiments. Things and events they know to be non existent.
Just a few famous examples from physics:
-Newton’s bucket. Newton knew that our universe does not contain a single object (the bucket filled with liquid). But the thought experiment illustrated interesting points that advanced science.
-Maxwell’s Demon. Again, Maxwell knew that there is no such demon; that wasn’t the point. the thought experiment illustrated interesting points that advanced science.
-Schrodinger’s Cat. Again, no physicist takes such a being seriously. It is merely meant to demonstrate a point about the conceptual foundations of quantum mechanics.
-Objects with mass riding on a beam of light. Used by Einstein when he fully knew that such actions are impossible.
-Time machines. Most theoretical physicists do not believe they are physically possible and yet there are plethora of papers in physics journals using these fictional objects to demonstrate points about our very real world.
Additionally, there are also objects that are very well possibly non existent but worth considering anyway such as strings and even time (which may be illusory according to many physicists today). But if these things turn out to be not real, they would still be considered useful fictions that advanced science. The conceptual tools developed in thinking about them makes it worthwhile to develop even if it turns out they don’t exist.
The most obvious example of a useful fiction is the mathematical world assuming physicalism is true as most scientists (and I’d imagine Coyne) would proclaim allegiance to that doctrine. Numbers may not exist as such but they are useful for the advancement of knowledge.
But Coyne may respond that in all these cases, there is some criterion or criteria distinguishing the putatively non real but useful objects from their non-useful counterparts. But then the onus is on him to show what that criteria is (I’m sure philosophers of science would love to know. What a time-saver for scientists that would be!).
Coyne may respond that no such criteria is necessary for it is just plain obvious that imaginary things like god are too silly to be useful to advance knowledge about our world while imaginary things like rotating buckets in otherwise empty universes, Maxwell demons, etc are not. But because his intuition is not shared among many others including philosophers, his intuition shouldn’t be taken any more seriously.
Here’s a more positive reason Coyne is wrong. The point of the Templeton project is free will in the face of certain kinds of certain knowledge (of future events, etc). The notion of god is merely a rhetorical device.
It may very well be possible that one day technology will allow prediction to be very accurate so that we can have what was once thought to be god-like epistemic faculties. If that is the case, it is useful to think deeply about free-will and moral responsibility in counterfactual terms to illustrate the conceptual structure of the concepts now important to us. God is only used derivatively to analyse the important concepts that need elucidating.
Coyne misses the whole boat in thinking the god is the primary object to be analysed in this project; it’s not. Free will, moral responsibility, the nature of time and knowledge about time is, things that even a scientists should admit are well worth investigating. If fictional objects helps facilitate that venture as Newton’s bucket, Maxwell’s Demon, etc has for science, then so be it.