Perakh on Barr: Rejoicing in Materialism

Via the Panda’s Thumb comes notice of Mark Perakh’s review of Stephen M. Barr’s Modern Physics and Ancient Faith (2003). I recommend reading the whole review; Perakh demonstrates that Barr’s book, like Ken Miller’s Finding Darwin’s God (1999), offers some lucid descriptions of modern science but devolves into poor reasoning and non sequiturs when it touches notions of faith.

None of Barr’s arguments or Perakh’s counter-arguments are particularly new (which is one sign of how decrepit a business this “natural theology” really is). Barr organizes his book by describing successive “plot twists,” discoveries which supposedly upset the tidy materialism of a century ago. You could guess that quantum mechanics figures prominently; a couple linear operators fail to commute, and people run around saying reality’s been undone. Kurt Gödel also makes an appearance:

The “Fourth Plot Twist” is about the question of whether mind is just a machine, a kind of a “wet computer”, or something more that that. Barr admits that arguments against the “materialist” interpretation of mind have mostly been philosophical. Since science cannot be held responsible for philosophical arguments, Barr wants to find anti-materialist arguments regarding the essence of the mind within science itself. He can’t do so, so the second best thing seems to him to find such arguments in mathematics, which seems to be so closely intertwined with science. He allegedly finds such arguments in Gödel’s famous theorem.

When I haven’t eaten, a sensation exists in my mind which I label “hunger.” Eating makes this sensation go away. Ingesting a material called “aspirin” (which sounds more provocative if you call it “acetylsalicylic acid”) makes the pain perceived by my consciousness go away. Four centuries before Herod, Hippocrates was already saying, “Men ought to know that from nothing else but thence [from the brain] come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations.” If you read Carl Zimmer’s excellent Soul Made Flesh (2004), you can get the juicy details on how the ghost was pushed into the gaps: by Newton’s time, Thomas Willis had already divided the human mentality into a “rational soul,” which was the immortal and immaterial part responsible for the highest functions of reasoning, and the “sensitive soul,” which processed sensory input and did all the things which Willis found could be affected by physically perturbing the brain. When interviewed on All in the Mind, Zimmer said,

The funny thing is that in describing the sensitive soul and in the process describing how the brain works he was able to describe all sorts of things, all sorts of very complex kind of behaviours he was able to describe memory, he was able to describe learning and language, he was able to describe emotions, dreams, all of these things are what we would call a life of the mind in terms of the sensitive soul and the brain. So you kind of wonder after a while well what’s the rational soul there to do anymore.

When everyday experience indicates that the mind is at least partway matter, and when science has done nothing except drive the immaterial part into irrelevance, where do the mystics find succor? Why, in quantum physics and Gödelian incompleteness, of course!

We’ve been deep into this garden of forking paths before. Science After Sunclipse has hosted my own rant on the subject, which offers links into the literature. Among that literature, a good guide to the Gödelian argument is Scott Aaronson’s “Quantum Computing Since Democritus” Lecture 10.5.

Well, I’m off to give my second introductory quantum mechanics lecture for math people. Time to leave the hazy sophistries behind and evaluate some commutators!