[hnax]

"if you look back at Thomas Aquinas's writings on the soul with a modern bio understanding, [...] his conception of the "soul" is just his attempt at understanding metabolism without any solid physics or chemistry. [...] up until very recently the one last bastion of unexplained behavior where the religious could justify their belief in the soul was the intellect."

Not an expert on Aquinas but as a theologian he should have had to go no further than the opening book of the Bible, Genesis 1:26,27, where God says: "Let Us (plural) create Man in Our (plural) Image. [...] And in His Image He created Them, Male and Female." Indeed, that defines Man, Male and Female: Image bearers of God. How? Through the indwelling of the Holy Spirit -- therefore, God is a Trinity, a Father, Son, Spirit perfectly loving relationship.

"AI is a direct assault on this final motto, as it is concrete evidence that many of the "intellectual" outputs of the soul could, at least in principle, have a naturalistic explanation. (There was plenty of evidence of the intellect being fully naturalistic prior to AI, but it wasn't the kind of irrefutable "here's a fully natural thing that does the thing you said natural things couldn't do" evidence)."

I can't see how "AI is a direct assault on this motto". Man's actions are most often far from rational, and unexplainable from an intellectual point of view. Rather, Man's intentions greatly exceed that of naturalist animals, both positive in doing good, and negative in doing evil. It all points to a fundamental difference between Man (who has a Soul) and Animal (who hasn't). The Soul is the seat of Man's passions, and it's a hard thing to control -- impossible even.