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Review of Plantinga & Dennett’s “Science & Religion: Are They Compatible?”

When I found out that Alvin Plantinga and Daniel Dennett co-authored a book, I was shocked. I could not think of two more diametrically opposed philosophers. It turned out that the book, entitled “Science and Religion”, resulted from a debate between the two famed philosophers at the American Philosophical Division Meeting in Chicago for 2009. The book consists of alternating short readings from each philosopher. The book contains a transcript of the original debate along with two more essays from each philosopher. Having now read the book, I think that Plantinga largely missed the point of Dennett’s arguments and that Dennett was probably more terse than he should have been.

The debate organisers had asked the two philosophers to discuss whether science and religion were compatible. However, the debate topic promptly changed when both philosophers agreed that there was no logical inconsistency between theism and science.

I’ll start by describing the arguments given by the respective parties and then offer commentary on some aspects of Plantinga’s argument I found problematic. Then I will briefly describe the response that I think Plantinga should have given to Dennett, followed by the response that I think Dennett would have given.

Plantinga argues:

1. Theism — in particular, Christian theism (Plantinga calls this “classical theism”) — is compatible with modern evolutionary theory. According to Plantinga, evolutionary theory is consistent with the idea that God guided the evolutionary process. One might object that evolution is random (and is therefore unguided). However, no part of evolutionary theory states that evolutionary events do not have causes; in fact, there are (often) causes cited for mutations. One such cause could be divine intervention.

2. The reliability of our beliefs is inconsistent with the conjunct of evolution and naturalism (where naturalism is *defined* as strong atheism — i.e. as the belief that are is no God or god-like beings). Plantinga argues that evolution cares only about adaptivity, not about truth tracking.


3. In response to (1): True, at least some forms of theism are consistent with evolution. But many things are logically consistent with evolution and that they are consistent is not evidence that theism is the case. Consider Supermanism — the thesis that Superman (son of Jor-El and an alien from the planet Krypton) caused the Cambrian explosion.

In response to (2): Dennett provides two replies:

4. Human brains evolved to track truth; that they do so is a sign that they are functioning properly. Just as the proper functioning of our hearts is to pump blood, the proper functioning of our neurophysiology is to produce correct beliefs about the world. Importantly, Dennett argues that the various parts of our bodies have functions to which they were tuned by evolution. Our hearts pump blood efficiently because that is the function they evolved to have. Brains track truth because that is what brains were evolved to do. So, evolution *is* truth tracking after all.

5. While it is true that our beliefs are, at least in part, the product of our neurophysiological states, they are also the product of our collective cultural evolution, discourse, and deliberation. So, while there might be poor beliefs that are produced by evolution, cultural evolution tends to expunge the bad and leave us with the good (this is why scientific — or, more generally, intellectual — progress is possible at all).


6. In response to (3) (in particular, to Supermanism): Plantinga characterises the Superman thought experiment as trying to show that theism is absurd (or just as absurd as supermanism). Plantinga argues that Dennett, and the other New Atheists, may think that theism is absurd (or as absurd as Supermanism), but they have not provided an argument to show this point (or so Plantinga asserts). Plantinga argues that since there are a tremendous number of religious people in the world, and they do not appear to be irrational, it’s not clear that theistic belief is irrational. Thus, it would be incumbent on the New Atheists to argue for the irrationality of theism, something which Plantinga charges they have not done.

7. In response to (4): Plantinga does not think that organisms need to have accurate belief states in order to survive. Rather, organisms only require unconscious indicators that result in “correct” actions when provided with a given stimulus.

8. Plantinga does not provide a response to (5).


I think that there are a number of problems with Plantinga’s strategy. One particularly vexing problem concerns (6). Plantinga mischaracterises Dennett’s argument. Arguing that theism is absurd (or as absurd as Supermanism) would be a rather poor rhettorical strategy; after all, Tertullian* notwithstanding, presumably no one holds beliefs which they think are absurd (again, in the Supermanism sense). However, that’s not what Dennett appears to be arguing.

The argument which Dennett presents concerns the burden of proof.

When Plantinga argues that theism is compatible with modern evolutionary theory, Dennett is right to respond with agreement. There are many things which are logically consistent with our best scientific theories, but the more interesting question is which of those things is the case. Supermanism is one idea which is logically consistent with our best scientific theories, but we do not think Supermanism is something that anyone should believe. Thus, Dennett presses Plantinga to do more than just argue for the logical consistency of theism with evolution. Dennett asks, can Plantinga provide us with a positive argument for theism? Dennett’s argument was categorically not to assert that theism is an absurd claim (though, no doubt, Dennett does think that).

In this book, Plantinga does not provide us with a positive argument for theism; instead, all he can offer is an argument against what he calls naturalism (really, a strong form of atheism). However, to be consistent with the rest of his work, there is a response that Plantinga should have given to Dennett instead of the one that he gave.

Plantinga should have responded that he does not need to give a positive argument for classical theism. Plantinga thinks that there is an additional sense — the sensis devinitatis — which provides human beings with non-propositional information concerning the existence of God. On Plantinga’s account of religious justification, theists are justified in their beliefs because belief in God is properly basic in virtue of having been caused by the sensus divinitatis. On Plantinga’s account, theists are people who have the proper sort of sensory experience to justify god-beliefs. Just as we do not ask people to justify that they are having the experience of the color purple when they see a purple object, Plantinga thinks people do not have to justify their having theistic beliefs.

In turn, Dennett could have responded with at least two arguments:

–that the best explanation of religious belief is not that it is caused by the sensus divinitatis. Rather, the best explanation would be in terms of standard evolutionary psychology, cultural evolution, sociology, anthrology, etc (that is, the sort of thing Dennett details in “Breaking the Spell”). Naturalistic (though not in Plantinga’s sense!) explanations of religious belief and  experiences are capable of explaining much more than classical theism (for example, they can give good explanations of the global diversity of religion. They can also explain why we see the sort of religions that we do and not others, etc).

–even if the best explanation of religious belief was the sensus divinitatis, if non-theists are truthful about their belief states, then they apparently lack the sensus divinitatis (or atheists have an inactive sensus divinitatis, etc). If theists would like to convince non-theists then it is incumbent on them to provide other lines of argument/evidence than to appeal to non-propositional sensory experiences which are closed off to the rest of us (or so they would claim). Theists certainly do not have to convince non-theists, but one would think that the point of debate is to convince those who disagree with oneself. Thus, while some theists might claim that they do not want to convince others, they should refrain from asserting arguments for their position. Furthermore, given Plantinga’s account of religious beliefs, theists might think that convincing an atheist that God exists would be rather like trying to convince a blind person that you are experiencing purple. Since such an endeavour would be utterly futile, debate would be pointless. However, Plantinga both participated in a debate with Dennett and writes books arguing for theism. Thus, Plantinga presumably thinks that there is a point to the debate.


*Tertullian famously stated: “Credo quia absurdum” — “I believe because it is absurd.”