Book review: Modern Physics and Ancient Faith

Modern Physics and Ancient Faith
by Stephen Barr (2003)

Trying to relate religion and science is a perilous enterprise; philosophy is supposed to be the glue that fits them together.  Professor Barr avoids many dangers by taking a limited goal.  Materialists, he says, often claim that science shows the universe looking more like materialism would expect it to look like than what religion would expect it to look like.  While not a proof of materialism, it would certainly count in its favor.  Barr contests this claim, saying that while it may have been true one hundred years ago, the last century of developments in physics, cosmology, and mathematics have reversed the situation, and the universe now looks much more like what a Christian would have expected.  Of course, the current picture may change again, and even if it doesn’t materialism would remain logically possible.  Still, the “natural reading” of things has moved markedly in our favor.

Barr focuses on a few claims that he treats as natural to the religious worldview:  that the universe had a beginning in time, that it was designed at least partly for our habitation, and that there is an immaterial element in human consciousness.  None of these are demanded by theism, but they have been assumed by theists commonly enough that it is a fair list of things to investigate.  [Materialism is then defined as disbelief in God and an immaterial component of the mind.  Thus, Roger Penrose is called a “materialist” even though he famously (notoriously?) believes in a Platonic realm of mathematical truth.]  The relevant discoveries of modern science are then the big bang theory, anthropic coincidences in the fundamental constants of the universe (that the universe is “fine tuned” for life), the Lucas-Penrose argument from Goedel’s theorem that the human mind cannot be a computer, and the Copenhagen interpretation of quantum mechanics (which seems to place the observer outside the system).  That none of these force a non-materialistic conclusion is granted, but the wild conjectures materialists seem driven to make show that they do fit somewhat uncomfortably in their system.

That’s the plan of the book.  Now some details about specific parts.

I’m not sure, after inflationary theory, that the universe having a beginning is necessarily the most natural assumption anymore, so I would actually call that one a tie for materialists vs. religious.  Barr is very good on showing that a quantum creation of the universe doesn’t vitiate the cosmological argument, because the zero-universe vacuum state is not a metaphysical “nothing” but is already the state of a system with a great deal of structure (non-necessary structure, freely specifiable by the theorist).  Also that having a multiverse / string landscape doesn’t really answer the “fine tuning” design argument, because one must specify the laws of physics just right to get an acceptable multiverse.  This is an interesting and important point, one I think probably true, and I would have liked to hear more how generic appropriate multiverses are for general Lagrangians.  I was pleased to see him making an argument that I have also made, that evolution (and, more generally, the assembly of stars, planets, crystals, etc) is not about order emerging from absolute chaos, but about order arising from deeper order.  (He even provides a sort of measure of order, which I failed to do, based on symmetries.)

The discussion of the argument from Goedel’s theorem is admirably clear.  I was convinced of its power after reading John Searle’s critique of it, in which Searle is willing to reject the validity of mathematics to avoid its conclusion.  That is what asserting that our minds are inconsistent (not merely fallible–I’m grateful to Barr for making the distinction clear to me) formal systems amounts to.  The conclusion that our minds are not formal systems, not purely algorithmic, not computers, is certainly remarkable, but I would not conclude that there is anything immaterial about the mind’s operation.  The algorithmic model may well be an overly narrow model of what a materialistic brain could do.  Barr’s point, though, is his usual modest one:  the evidence confirms religious expectations.

I admit that I am one of those people Barr mentions who refuses to grant consciousness some unique role in quantum mechanics out of sheer prejudice.  However, Barr holds a somewhat subjective version of the Copenhagen interpretation–going so far as to claim that a system can have multiple wavefunctions, one for each observer’s state of knowledge, which while not a fringe view is probably not the majority position (not mine:  I’m much more of a wavefunction realist; only density matrices have probabilities from observer ignorance)–which is in tension with his argument that quantum mechanics shows there to be something special about consciousness.  It seems to me that wavefunction collapse has to be an objective thing to make a claim like that.  What seems more consistent with his own reading of quantum mechanics is that observers play a distinct role in it not because they are special in reality but because they are special in the formulation of the theory; it’s a theory about outsiders’ observations, not a theory of reality as a whole.  This issue aside, I agree with Barr’s arguments against the many-worlds interpretation, against existing pilot wave theories, and against the idea that decoherence somehow makes all these problems go away.