A couple of posts back, I touched on Stephen Hawking's No Boundary proposal and why it was influential to my deconversion. Predictably, out come theists trumpeting the sophisticated philosophers of antiquity to argue against a theory which deals with quantum mechanics. This cannot go well. If we atheists love our physicists, then man, those theists sure do love their ancient philosophers.
But I tend to find such philosophy to be little more than sophistry, for reasons that seem to me should be obvious. The philosophers of antiquity did not have access to the sciences of general relativity or quantum mechanics, or even Newtonian physics for that matter. They attempted to make ontological declarations about the world by logical inference, achieved through rational introspection.
Well, the problem is that science has revealed that reality often defies our intuitions. Take, for example, quantum mechanics versus classical (Newtonian) physics. In Newtonian physics, you can determine the position and velocity of a baseball through a regress of causal events. The ball was struck by the bat and such-and-such an angle at such-and-such a speed, which will make it accelerate at x rate to y speed at z trajectory, etc. etc. You could further take this causal chain back to the human body and the force exerted by the muscles of the human body to determine the angle and velocity of the bat, and so on.
You can't do anything like that in quantum mechanics. In quantum mechanics, the position or velocity of a particle is determined probabilistically. Likewise with the rate of nuclear decay, the spontaneous emergence of virtual particles, or the spin of entangled particles. Classical laws of causality simply become nonsensical at the quantum scale, as do the "laws" of logic. A particle can be described as either wave-like or point-like, which is indeterminate until it's measured – and there's evidence that a particle can be both wave-like and point-like simultaneously, contrary to the "law" of noncontradiction. And because the above phenomena can only be determined probabilistically, they defy explanation by modus ponens – cause and effect or "if a, then b".
I've heard theists attempt to argue that there may be some sort of classical logic at work in quantum mechanics that we just haven't detected yet. But while it may give theists some comfort to crouch in the annoyingly indefatigable position of "you can't disprove it!", we have good reasons to think that classical causality doesn't work at the quantum scale – namely, that we have successfully described, with astounding accuracy, all of that particles and physics that are relevant to human existence. And we've done it all without a shred of evidence that the laws of classical logic are at play.
Ancient philosophers inferred the laws of logic from their everyday human frame of reference. But we don't exist on a subatomic scale any more than we exist in the singularity of a supermassive black hole. We can't intuit about those frames of reference because they don't factor into our subjective experience at all. Instead, we have to use observation and experiment – and it turns out that predictions made by quantum mechanics are the most accurate in any science ever developed. One famous analogy describes it as being able to predict the width of the United States with a margin of error the width of a human hair. Despite its persistently counter-intuitive nature, quantum mechanics has illuminated our understand of the fundamental workings of reality more than any other science in human history.
And why should we expect reality to conform to our intuitions? Why should we expect that classical philosophers who had only their intuitions ought to be able to tell us more profound things about reality than particle-smashing physicists? The only reason I can gather is the obvious one: wishful thinking. The philosophers of antiquity seem to lend an air of credibility to theistic beliefs by virtue of their esoteric vernacular and semantic obfuscation. To accept that modern science has undone much of classical philosophy is to concede that arguments that have held sway among believers for centuries are founded on misguided premises and incomplete facts.
That's why Hawking said "philosophy is dead" – it's failed to keep up with science. And that's why arguments about "potentiality and actuality", "prime movers", or "First Causes" are irrelevant in light of today's scientific progress. It's discomforting for some believers, and instead of embracing this knowledge they cling desperately to the comforting sophistry of antiquity. But as Carl Sagan said: it's far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.