Thud challenged that my comment “The belief in a soul becomes increasingly more difficult to maintain in the light of evolutionary psychology and advances in cognitive science” is “an unfounded assertion”:

How does it become increasingly difficult to believe in a soul? It may be increasingly difficult to believe that one’s sense of self is entirely separable from the physical form, but that doesn’t mean there’s no soul. There’s an enormous chasm between saying “who we are is changed by what we are” -- I think that’s a safe statement -- and saying "we are nothing but meat."

It’s increasingly difficult because there are increasingly fewer things we can attribute to "the soul." Thud himself admits “who we are is changed by what we are,” but how is that logically possible if who we are intrinsically is spiritual? How can the physical affect the spiritual? The supposed miracles of the Bible show the reverse is generally the accepted view, but the belief in the soul requires the opposite to be true. A few questions then:

First, how could the soul be affected by the body? Simple -- memory. Memory and memory alone is what makes human identities possible, and if the soul is in any way equated with our “identity” (and if it’s not, what’s the point?), the memory will be a necessary component. So neurons firing a certain way in the hippocampus, the amygdala, or the mammillary somehow deposit a copy of activity in the soul? The soul is an all-in-one card reader? How does it work without stepping outside the boundaries of logical and basic scientific principles?

Second: we’re talking about the soul without even considering where it came from. If we believe in a God, then we’re his creation; if we believe the theory of evolution is a better explanation than the Book of Genesis, then we’re the products of millions of years of cosmic chance; if we want to hold both beliefs at once, we call ourselves proponents of intelligent design. I hold to option two. It’s the option that has the most scientific evidence. Now, if I hold to that option and assert that there’s a soul, then where the hell did it come from? How did millions and millions of years of cosmic bumper ball create something spiritual?

Third: What effect do sudden changes in a person’s identity have on the soul -- indeed, how is that even possible? What sort of “sudden changes” do I have in mind?

Phineas Gage, with his famous three-foot-seven-inch railroad spike through his head.

Some months after the accident, probably in about the middle of 1849, Phineas felt strong enough to resume work. But because his personality had changed so much, the contractors who had employed him would not give him his place again. Before the accident he had been their most capable and efficient foreman, one with a well-balanced mind, and who was looked on as a shrewd smart business man. He was now fitful, irreverent, and grossly profane, showing little deference for his fellows. He was also impatient and obstinate, yet capricious and vacillating, unable to settle on any of the plans he devised for future action. His friends said he was “No longer Gage.” (Source)

But we don’t have to look to 19th-century tragedies. Think lithium, anti-depressants, Prozac. I recall meeting with my grad school advisor and discussing this. “How many Kierkegaards have we destroyed with Prozac?” Indeed -- Kierkegaard, Mahler, and how many other manic-depressives would never have created their classics if they’d been born in the late twentieth century.

All the way back in 1979 there was an article about this. The abstract:

Twenty-four manic-depressive artists, in whom prophylactic lithium treatment had attenuated or prevented recurrences to a significant degree, were questioned about their creative power during the treatment. Twelve artists reported increased artistic productivity, six unaltered productivity, and six lowered productivity. The effect of lithium treatment on artistic productivity may depend on the severity and type of the illness, on individual sensitivity, and on habits of utilizing manic episodes productively. (Source)

But we don’t even have to look at medication for drastic changes. Watch some of your friends when they’re drunk.

So it’s not that I’m suggesting that there isn’t a soul. I’m simply saying that logic and science combine to show that there are, as Steven Pinker expressed it, fewer and fewer hooks on which to hang the soul.