Theistic Notebook

March 4, 2011

Alvin Plantinga – Science and Religion: Are They Compatible? Part 2

Alvin PlantingaWhat follows is part 2/3 of my transcription of Plantinga’s opening statement during his exchange with Daniel Dennett in 2009. The mp3 is available here. Also, Plantinga and Dennett co-authored a book shortly after this debate.

“Science and Religion: Where the Conflict Really Lies”
Speech delivered by Alvin Plantinga at the 2009 American Philosophical Association Central Division Conference.

Section 2: Broader Anti-Theistic Arguments from Evolution

So Darwinism as such doesn’t include or imply the proposition that the process is unguided.  What about broader anti-theistic arguments involving evolution?  I’m aware of three sorts of arguments proposed here.  First there is the claim that evolution undercuts the argument from design, thus reducing the rational support (if any) enjoyed by theism.  Second, there is the claim that the process of evolution so wasteful and productive of suffering is not the sort of process God would use or permit.  And thirdly, there is the thought that unguided evolution as a hypothesis is superior to the hypothesis that the process of evolution has been guided or orchestrated by minds (divine or otherwise), because it is simpler and more Occamistic.  None of these objections, I believe, is promising.  While I can’t deal properly with any of them, let alone all of them in the time I have, I’ll briefly outline a response to each.

Start with the claim that evolution undercuts the argument from design, thus making it less reasonable to accept theistic belief.

According to John Dupré, “Darwinism undermines the only remotely plausible reason for believing in the existence of God.” [iv]

That is…the argument from design.  Now it’s reasonable to think that evolution makes it somewhat easier to be rational or sensible in accepting atheism.  Prior to 1859, there simply weren’t decent answers to the question: if this abundant variety of life wasn’t created by God, how did it get here?

In this connection Richard Dawkins says, “Darwin made it possible to be an intellectually fulfilled atheist.” [v]

But making it easier to be a rational atheist doesn’t as such make it harder to be a rational theist, and doesn’t as such create a religion/science conflict.  And how much support does the argument from design actually offer theistic belief anyways?  Perhaps it suggests belief in the existence of a very powerful, very knowledgeable being (or group of beings).  But that’s a long ways from theism.

In any event, however, current molecular biology may offer the materials for a different sort of argument from design, as explained in the much maligned Michael Behe’s recent book, “The Edge of Evolution.”  Michael Behe is indeed much maligned.  His argument is one of the few serious and quantitative arguments in this area.  We have the living cell, both prokaryotic and eukaryotic, with its stupefying complexity and its multitude of elaborately complex protein machines.  Behe argues that unguided natural selection is probably incapable of producing these protein machines.  His argument is quantitative and empirical rather than a priori.  Its centerpiece is the saga of the malaria parasite, Plasmodium falciparum, and its long trench warfare over the human genome.  I don’t have the space here to outline this argument, but to me as a layman the argument seems reasonably powerful though very far from conclusive.  If Behe is right, or anywhere nearly right, the probability of the existence of the cell as we find it is much greater on theism than on naturalism.  And if this is so, the argument from design is reinstated at a deeper level.  What current biological science takes away with one hand, it restores with the other.  But the real point lies in a different direction.  Belief in God is seldom accepted on the basis of the teleological argument, or indeed any argument or propositional evidence at all.  Both untutored observation and current research in the scientific study of religion suggest that a tendency to believe in God (or something very much like God) apart from any propositional evidence is part of our native cognitive endowment.  Furthermore, if theistic belief is true, it probably doesn’t require propositional evidence for its rational acceptability.  As I argued in this book, “Warranted Christian Belief,” if theistic belief is true than very likely it has both rationality and warrant in a basic way: that is, not on the basis of propositional evidence.  If theistic belief is true, then very likely there is a cognitive structure, something like John Calvin’s sensus divinitatis, an original source of warranted theistic belief.  In this way belief in God, like belief in other minds, has its own source of rationality and warrant and doesn’t depend on arguments from other sources for these estimable qualities.  The demise of the teleological argument (if indeed evolution has compromised it) is perhaps little more of a threat to rational belief in God than the demise of the argument from analogy for other minds is to rational belief in other minds.

Second, there is a suggestion made by Gould and others that the waste and suffering involved in evolution is evidence against theism.

Phillip Kitcher puts it like this, “When we envisage a human analogue presiding over a miniaturized version of the arrangement…it’s hard to equip the face with a kindly expression.”

And then it goes on to suggest, “Had a benevolent creator proposed to use evolution under natural selection as a means for attaining his purposes, we could have given him some useful advice.” [vi]

I’m not sure how such advice would be received [audience laughter], but of course we don’t require current evolutionary theory (or current science at all) to tell us that the animal world is full of predation, death, pain and suffering.  Alfred Lord Tennyson noted that “nature is red in tooth and claw” well before 1859 and no doubt some suspected it even earlier [audience laughter].  Still current science gives us reason to believe that suffering and death have afflicted the human and animal world for a much longer time that was ordinarily thought before the nineteenth century.  It has therefore given us information about the extent and duration of animal suffering … including human suffering.  The first thing to see here I think is this is a special case of the so-called “problem of evil”: a problem that is alleged to afflict theistic belief.  Sin and suffering do indeed constitute a problem or perplexity for theism, although it may be hard to specify precisely what the problem is.  Most atheist thinkers have given up the idea that the existence of sin and suffering is logically incompatible with theistic belief.  Some kind of inductive or probabilistic anti-theistic argument is presumably what’s at issue.  It has proven surprisingly difficult, however, to give a really plausible statement of a probabilistic argument from evil.  And as these arguments become more complex, they also seem to become less convincing.  Surely, however, sin and suffering create some kind of problem or at least perplexity for theists.  The existence of so much suffering and hurt in God’s world certainly seems to call out for an explanation of some sort.  And what current biological science adds to the problem is that predation, suffering, and death have been going on for a very long time.  But does this put any additional pressure on the various theistic or Christian responses to suffering and evil?  My own favorite response is the “O felix culpa” response, according to which all of the really good possible worlds involve divine incarnation and atonement (or at any rate atonement).  But then all the best possible worlds also involve a great deal of sin, and as a consequence a great deal of suffering.  Some of this suffering is on the part of non-human creatures.  Christians think of suffering, both human and non-human, as due in one way or another to sin, although not necessarily to human sin.  There are also Satan and his minions who may, as C.S. Lewis suggests, be involved in one way or another in the evolution of the non-human living world.  But learning that sin and suffering has been going on for longer than we had originally thought shouldn’t raise any additional difficulties for the “O felix culpa” response.  Suppose we learn that our world with all its problems heartaches and cruelty will endure for millions of years before the advent of the new heaven and the new earth.  That wouldn’t have much bearing, one thinks, on the viability or the satisfactoriness of this response to evil.  The new heaven and the new earth, after all, will exist for a vastly longer period than our current sad and troubled old world.  Officially at least, it will be such a long period that the length of time our current sad and troubled old world exists isn’t any proportion of it at all.  But the same goes, I should think, for our learning that our world (with all the ills there too) has gone on much longer than originally thought.  Current science shows that suffering, both human and animal, has gone on much longer than previously thought; but it doesn’t thereby diminish the value of Christian responses to the problem of evil, and in this way doesn’t exacerbate that problem much if at all.

Finally, there is the claim—perhaps made more often in the oral tradition than in print—that the hypothesis of unguided evolution is simpler and more in accord with Occamistic injunctions than the hypothesis that God or other intelligent beings have guided the course of terrestrial evolution.  Here, two points are relevant.  First, even if unguided evolution is more Occamistic than guided evolution, it isn’t at all clear that the former is—all things considered—superior as the hypothesis to the latter.  It involves fewer kinds of beings, yes, but that isn’t the only relevant consideration.  Another is their respective likelihoods, that is, the probabilities of the living world—more exactly, the variety of the living world—coming to be by way of these two hypotheses.

(1) Let ‘D’ be the proposition that the variety of the living world is come to be by Darwinian processes.

(2) ‘E’: the biological evidence

(3) ‘G’: the proposition that evolution is guided

(4) ‘U’: the proposition that it is unguided

Then our question is which is greater:  the probability of ‘D’ on ‘E’ and ‘G’, or the probability of ‘D’ on ‘E’ and ‘U’?

It is, of course, overwhelmingly difficult to make anything like reasonably precise judgments here; but perhaps we can make sensibly comparative judgments.  Consider first: P(D/E&G).  Clearly God could have created living things by way of natural selection: causing the right mutations to arise at the right time, preserving the right populations from disaster, and so on.  He could also have allowed other intelligent creatures to be involved in the whole process.  Again, it is overwhelmingly difficult to estimate the probability that this is the way in which it has in fact happened.  But P(D/E&G) is perhaps not terribly low.  What about P(D/E&U)?  Going all the way back to St. George Mivart, critics have expressed serious doubt as to whether the eye, for example, could have come to be by way of unguided natural selection operating on random genetic mutation.  Could have that is, apart from absolutely stunning improbability.    The eye, the mammalian brain, and other organs remain difficult problems for unguided evolution; but the really hard problem here for unguided Darwinism isn’t the development of macroscopic organs such as eyes and hearts.  The hard problem rather is at the microscopic molecular level: the stupefying complexity of the living cell, both prokaryotic and eukaryotic.

So for example, Bruce Alberts (President of the National Academy of Sciences when he wrote this) says, “Nearly every process in a cell is carried out by assemblies of 10 or more protein molecules…Indeed, the entire cell can be viewed as a factory that contains an elaborate network of interlocking assembly lines, each of which is composed of a set of large protein machines…” [vii]

It’s only in the last half century or so that this enormous complexity has come to view.  The eminent scientist Ernst Haeckel sums up nineteenth century opinion when he declared the cell “a simple little lump of albuminous combination of carbon.”

Of course, it’s widely assumed that in fact the cell must have come to be in that fashion.  But there is little by way of serious argument for the conclusion that its coming to be in this way is less than prohibitively improbable.  On the other hand, as I said above, Michael Behe has proposed a serious and quantitative argument for the opposite conclusion.  Given the stunning complexity of the living cell with its enormous complication, together with what we know about mutation rates, the age of the earth, population size, and the like: it seems reasonable or maybe not unreasonable to estimate that P(D/E&U) is exceedingly low.  Perhaps orders of magnitude lower than P(D/E&G).  If this is right then even if we accept ‘U’ as Occasmistically superior to ‘G’, it is inferior to ‘G’ in that the relevant likelihood is lower.

But again, the real point lies in a different direction.  The theistic noetic structure already, of course, includes the existence of God.  Relative to that noetic structure, therefore, there is no additional Occamistic cost in the hypothesis of guided evolution.  As an analogy: suppose we land a spaceship on a planet we know is inhabited by intelligent creatures.  We find something that looks exactly like a stone arrow head, complete with grooves and indentations apparently made in the process of shaping and sharpening it.  Two possibilities suggest themselves.  One: that it acquired these characteristics by way of erosion let’s say.  And the other: that it was intentionally designed and fashioned by the inhabitants.  Someone with a couple of courses in philosophy might suggest that the former hypothesis is to be preferred because it posits fewer entities than the latter.  He’d be wrong, of course.  Since we already know the planet contains intelligent creatures, there is no Occasmistic cost involved in thinking these structures designed.  The same would go for evolution.  Theists already accept divine design, and do not incur additional Occamistic cost by way of thinking of evolution as guided.  This objection to guided evolution would have more by way of teeth if we theists and atheists alike were starting from an agnostic position, and then the theists proposed to postulate the existence of a divine designer in order to explain the course of evolution.  That would be substantially like offering a theistic argument.  And then the availability of a non-theistic alternative hypothesis—providing the relevant likelihood wasn’t too overwhelmingly small—would indeed undercut the argument.  But of course, in this context the theist isn’t presenting a theistic argument.  She already accepts divine design, and hence the fact that guided evolution involves more entities than unguided evolution, is no reason in favor (with respect to her noetic structure) of the latter.  Since that is so, there is no conflict here between theistic religion and evolutionary science.

I’ve argued that contemporary scientific theories of evolution taken as including Darwinism do not entail the claim that natural selection is unguided.  But suppose I’m mistaken, or suppose instead that current evolutionary theory itself evolves in such a way that this claim becomes part of it.  This could certainly happen.  We can easily imagine the authorities in the textbooks stating the theory as such a way as to explicitly include the claim that natural selection is unguided by any personal agent.  After all, many (perhaps most) biologists believe that it is unguided.  Would that show that there is scientific evidence against theism?  Hardly.  We could imagine physics evolving in the same direction:  all the physics textbooks behind them endorsing general relativity … adding that the behavior of large-scale physical systems is never guided by any personal agents.  In either case, it wouldn’t follow that there is scientific evidence against theism.  Annexing a proposition p to one for which there is evidence doesn’t automatically confer evidence on p.  I learn that Feike is a Frisian lifeguard.  That increases the probability that he can swim.  It also increases the probability of the proposition: Feike can swim, and the next toss of this coin will land heads.  But it does not increase the probability that the next toss of this coin will land heads.  And even if, contrary to fact, there were scientific evidence for unguided evolution (and hence for atheism), that would by no means settle the issue.  Suppose there is scientific evidence against theism.  It doesn’t follow that theism is false or that theists have a defeater for their beliefs or that theistic belief is irrational or in some way problematic.  Perhaps there is also scientific evidence or otherwise for theism.

Second but more important: as I mentioned, if theism is true it is likely that it has its own intrinsic and basic source of warrant.  Something like the sensus divinitatis proposed by John Calvin or the natural but confused knowledge of God proposed by Thomas Aquinas.  If so, the warrant for theistic belief doesn’t depend on the state of current science.  Indeed, what Christians and other theists should think of current science can depend quite properly in part on theology.  For example, science has not spoken with a single voice about the question of whether the universe has a beginning.  First the idea was that it did, but then the steady state theory triumphed, then big bang cosmology achieved ascendancy, but now there are straws in the wind suggesting a reversion to the thought that the universe is without beginning.  The sensible Christian believer is not obliged to trim her sails to the current scientific breeze on this topic—­revising her belief on the topic every time science changes its mind.  If the most satisfactory theistic or Christian theology endorses the idea that the universe did indeed have a beginning (isn’t eternal let’s say), the believer has a perfect right to accept that thought.  If so, then even if there were scientific evidence against theism and no propositional evidence—­arguments, let’s say, scientific or otherwise—­in favor of it, it still might be both rational and warranted.

iv Dupre, John. John Darwin’s Legacy: What Evolution Means Today. Oxford University Press, 2003. 46.
v Dawkins, Richard. The Blind Watchmaker. W. W. Norton & Company , 1986. 6.
vi Kitcher, Phillip. “The Many-Sided Conflict Between Science and Religion.” The Blackwell Guide to Philosophy of Religion. William E. Mann. Wiley-Blackwell, 2004. 268.
vii Alberts, Bruce. “The Cell as a Collection of Protein Machines: Preparing the Next Generation of Molecular Biologists.” Cell. 92. (1998): 291.


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