In Chapter 4, Plantinga argues for the compatibility of god and science by way of quantum mechanics.
Quantum mechanics is something that even the physicists who work with it will tell is something that no one fully understands. I have some comments to make on Plantinga’s use of quantum mechanics, but first I want to spend some time reviewing it, distilling some of the basics for readers who, like me, may not have had much acquaintance with it.
Quantum mechanics refers to the idea that there are quanta, indivisible units of energy action. Particles jump between quanta depending on their wavelength and the amount of energy absorbed or emitted. Think of quanta as the “pixels” of reality.
Particle-wave duality tends to manifest itself at these scales where the wavelength of the particle as expressed by its energy and momentum is of the same magnitude as the system it acts within. Thus we use it to explain sub atomic activity but not the movements of the planets or the operation of combustion engines. Those types of things are explained using classical mechanics (think Isaac Newton).
The action of a system at the quantum scale is given by a waveform function. Because of our inability to measure certain quantum phenomenon, and the apparently random outcome of quantum activity, the waveform function is probabilistic. In other words, the waveform function describes the probabilities of a certain outcome, it does not necessarily tell us the outcome.
This not being able to see into the inner workings of quantum state changes has spawned a number of theories. Some believe that whatever is going on is deterministic, and some believe it is indeterministic. Among indeterministic theories are those that believe the waveform function resolves once the state is observed and those that believe the waveform function resolves randomly on its own. These are called waveform collapse theories.
Among the deterministic theories of quantum mechanics, you have the many worlds interpretation, which claims that all probabilities of the waveform function come into being in their own separate universes, and the pilot-wave theory, which holds that the wavelike nature of particles at particular wavelengths is the result of the action of waves upon the particle.
I’ll stop right here to fault Plantinga for not mentioning anything about deterministic theories of quantum mechanics. He practically acts as if quantum mechanics and indeterminism are the same thing. Of course he narrows in on the indeterministic theories of quantum mechanics because he needs these to be able to provide the necessary scientific justification for divine intervention. It reminds me of his omissions of alternative theisms in chapter 2.
Nevermind that the physicists themselves don’t agree on a theory. If anything, the conventional wisdom in current physics tends to lean to the Copenhagen interpretation, an indeterministic theory that holds that waveform collapse happens upon observation(measurement), with the many worlds interpretation coming in second. Plantinga’s vision of divine intervention favors the alternate indeterminate theory called GRW (Ghirardi-Rimini-Weber) that holds that waveform collapse happens at a random point. GRW is probably the theory with the strongest element of indeterminism; its outcome does not depend on an outside measurement but wholly on an apparently internal “random” process. It’s in this tight black box offered by one of many possible theories of quantum mechanics that Plantinga claims that science is not incompatible with god after all.
Even assuming that quantum mechanics isn’t compatible with deterministic certainty, Plantinga goes too far in assuming an irreducible uncertainty. And he must prove that, at the heart of quantum mechanics, there exists such an irreducible uncertainty, if he wants to insert the possibility of divine intervention. (This would be the corollary of intelligent design’s “irreducible complexity”.) The level of uncertainty surrounding quantum mechanics is at least partially reducible, if not fully reducible, given our current level of scientific understanding.
(The previous line of criticism was suggested to me in a paper by Andrew W. Lo and Mark T. Mueller titled “WARNING: Physics Envy May Be Hazardous To Your Wealth!”)
It’s a classic god-of-the-gaps argument. At least until science closes it, too. He says that even if an explanation comes along that eliminates his argument, faith is still a warrant for believing in divine intervention. And this is precisely the point at which Plantinga gives the whole enterprise away---the argument is a bit inconsistent, when you say that science has no right to assume what CAN’T be happening because our knowledge is limited, and then turn around and say what SHOULD be there. What Plantinga won’t do is the same thing Ken Ham wouldn’t do with Bill Nye, and the same thing no Christian apologist will do, is provide criterion regarding divine intervention or creation by which they would accept they are wrong. They are not bound by the scientific method while insisting that their opposition be.
If you are going to do that, then in a very practical way you are vouching for the NOMA principle. Just point to Gould and call it a day instead of writing a book trying to show how science “leaves room for god.”