In his recent book Warranted Christian Belief, Alvin Plantinga argues that the defender of naturalistic evolution is faced with adefeater for his position: as products of naturalistic evolution, we have no way of knowing if our cognitive faculties are in fact reliably aimed at the truth. This defeater is successfully avoided by the theist in that, given theism, we can be reasonably secure that out cognitive faculties are indeed reliable. I argue that Plantinga’s argument is ultimately based on a faulty comparison, that he is comparing naturalistic evolution generally to one particular model of theism. In light of this analysis, the two models either stand or fall together with respect to the defeater that Plantinga offers

Tedesco, Matthew

In his recent book Warranted Christian Belief (2000), Alvin Plantinga argues that the defender of naturalistic evolution is faced with adefeater for his position: as products of naturalistic evolution, we have no way of knowing if our cognitive faculties are in fact reliably aimed at the truth. This defeater is successfully avoided by the theist in that, given theism, we can be reasonably secure that out cognitive faculties are indeed reliable. I argue that Plantinga’s argument is ultimately based on a faulty comparison, that he is comparing naturalistic evolution generally to one particular model of theism. In light of this analysis, the two models either stand or fall together with respect to the defeater that Plantinga offers

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Theism, Naturalistic Evolution, and the Probability of Reliable Cognitive Faculties: A Response to PlantingaMatthew Tedesco, Beloit CollegePhilo 5 (2): 235-241 (2002)In his defense of theism most recently offered in his book Warranted Christian Belief, Alvin Plantinga presents what he takes to be a fundamental flaw in the position held by the defender of naturalistic evolution.  Specifically, the defender of naturalistic evolution is faced with a defeater for his position: he can have no way of knowing that his cognitive faculties, as a product of naturalistic evolution, are in fact reliably aimed at the truth.  This defeater is not, however, a problem for the theist: as products of an all-knowing, all-loving, all-powerful God who cares a great deal about us, the probability is very high that our cognitive faculties are indeed reliable.	At least three responses are available at this point for the defender of naturalistic evolution.  The first response would be to demonstrate why his position does not in fact have this defeater.  That is, after some careful presentation of his model, the defender would have to show that naturalistic evolution would indeed likely produce reliable cognitive faculties.​[1]​  A second response would involve a direct attack on Plantinga’s system of defeaters.  This route would allow for Plantinga’s analysis of the reliability of our cognitive faculties, while denying that this entails rejecting naturalistic evolution.​[2]​  While I do think that both of these routes (particularly the former) are promising, I will grant for the sake of argument that Plantinga is correct on this point, that naturalistic evolution is faced with a defeater.  Given that, then, I will instead opt for a third kind of reply: while it may well be the case that naturalistic evolution is faced with the defeater that Plantinga has in mind, theism is faced with a defeater.  More specifically, it is faced with precisely the same defeater as naturalistic evolution, and for the same reasons.​[3]​  After first presenting Plantinga’s discussion of naturalistic evolution and its defeater, I will discuss in detail precisely why theism is equally vulnerable.  If this is true, then Plantinga will be faced with a rather unpleasant dilemma: he must either reject theism for the same reasons that he rejects naturalistic evolution, or else he must entirely reject the category of defeaters as he presents them, rescuing naturalistic evolution along the way.The Defeater for Naturalistic Evolution	On the face of it, the defeater that Plantinga has in mind can apply to any model that takes as its focus the source of our cognitive faculties.  In other words, theism and naturalistic evolution provide two possible accounts concerning how we have come to have the cognitive faculties that we do have; for each, then, we must consider whether or not the model in question would provide for cognitive faculties that are reliably aimed at the truth.  If it happens to be the case that the probability of that model providing for cognitive faculties reliably aimed at the truth is either low or inscrutable, then the model faces a defeater for those faculties.  That is, if we have good reason to doubt that our faculties are reliable, then not only is our trust in those faculties undermined, but also undermined are all of our reasoning and beliefs brought about through or by those faculties.	Consider theism first.  By this model, according to Plantinga, we are the products of an all-knowing, all-powerful, all-loving God who loves us and cares a great deal for us.  To see if theism is faced with the defeater that Plantinga has in mind, we must consider whether or not our cognitive faculties would, by theism, be reliably aimed at the truth.  Given the nature of God, and of his relationship to us, not much reflection is required to recognize that the probability of us having reliable faculties would, by this model, be extremely high.  Given God’s characteristics, and how much he cares for all of us, it would be hard to imagine why he would provide us with unreliable cognitive faculties.  Plantinga explicitly makes this observation, noting that, “[g]iven that God would certainly want us to be able to know him, the chances are excellent that he would create us with faculties enabling us to do just that.”​[4]​  In light of this, then, theism avoids the defeater in question.	Next, consider naturalistic evolution.  By this model, we are not the products of a loving creator, but rather of a process of evolution that has spanned countless millennia.  Given thousands upon thousands of years of natural selection, we have arrived at this point in the present, armed with our current cognitive faculties.  Just as we did with theism above, then, we need to ask whether or not our cognitive faculties would, by this model, be reliably aimed at the truth; if so, then naturalistic evolution would also successfully avoid the defeater in question.  However, it does not, and the reason why begins with the important observation that “…natural selection isn’t interested in true belief but in adaptive behavior.”​[5]​  That is, evolution does not choose for the right sorts of beliefs, but rather it is solely concerned with the right sorts of behavior, and so our mental life need not at all impact adaptive behavior.  In light of this, then, we have no basis for having faith in the reliability of our cognitive faculties, and so naturalistic evolution faces the defeater that theism safely avoids.	This point is brought out more prominently when we consider that, even if beliefs do play an important role in choosing adaptive behavior, the probability of us having cognitive faculties reliably aimed at the truth is still either quite low or inscrutable.  That is, even though natural selection chooses for behavior, it may well seem plausible that beliefs must play a role in this process.  In light of this consideration, Plantinga observes the following:“[B]ehavior, if it is partly produced by belief, is also partly produced by desire: it is belief and desire, along with other things, that together produce behavior.  But then clearly there could be many systems of belief and desire that yield the same bit of adaptive behavior, and in many of those systems the belief components are largely false….”​[6]​Here, Plantinga is pointing out that even if beliefs do play a role in choosing behavior, the work is being done not by beliefs alone, but rather by belief-desire combinations.  Given this complex relationship, it may perfectly well be the case that the beliefs in question are in fact false–this is irrelevant, as long as they produce (for whatever reason) the right sort of behavior.	It is at this point that, for Plantinga, the defeater for naturalistic evolution takes center stage.  Given theism, the probability of us having reliable cognitive faculties was quite high; now, though, given naturalistic evolution, the probability of us having reliable cognitive faculties is low or inscrutable.  This is because natural selection is concerned only with adaptive behavior, and so need not be concerned at all with beliefs.  Furthermore, even if our beliefs do (plausibly enough) play a role in choosing behavior, beliefs alone are insufficient; rather, our actions only come from belief-desire combinations.  So, for example, I may have the false belief that forest fires are just the trees in a very bad mood; combined with the desire to avoid unhappy trees, this belief-desire combination will produce the right sort of behavior every time (namely, me fleeing from forest fires), and so I will be fit for survival.  Given these facts about naturalistic evolution, then, I can have no real confidence in the proposition that my cognitive faculties are reliably aimed at the truth.  According to Plantinga, therefore, naturalistic evolution contains a defeater for my faculties that theism successfully avoids.Theism and the Defeater	As I stated earlier, several avenues of response present themselves.  The first and most natural response here would likely be to reject Plantinga’s account of the role of beliefs in natural selection and argue that naturalistic evolution produces beliefs that are consistently reliably aimed at the truth.  We might also be tempted to grant that our beliefs are not reliable given naturalistic evolution, yet argue that this fact does not count as a defeater for naturalistic evolution.  What, though, if we grant Plantinga that naturalistic evolution does in fact contain this defeater?  Consider for a moment what we are granting.  Plantinga first points out that beliefs need not be involved at all in choosing for adaptive behavior, which is the sole concern of naturalistic evolution; and, even if they do play a role, it is not alone but rather in conjunction with desires.  So, then, beliefs need not play a role, and if they do, then they need not be true beliefs.  All this, then, leads Plantinga to conclude that the probability of naturalistic evolution yielding cognitive faculties reliably aimed at the truth is low or inscrutable.	At this point, it is crucial to observe that there is at least one model of naturalistic evolution that would yield reliable faculties.  I am not here yet attempting to motivate any criticism of Plantinga; rather, I am only attempting to describe as best as possible how Plantinga is presenting his objection to naturalistic evolution.  Beliefs need not play a role in choosing for adaptive behavior, but they might; even if they do, these beliefs need not be true beliefs, though again, they might be.  So, then, at least one model of naturalistic evolution is that in which beliefs do play a role in choosing for behavior, and these beliefs are true.  By this model of evolution, of course, the probability of us having reliable cognitive faculties is extraordinarily high, insofar as the model guarantees the truth of the beliefs.  The problem, though, is that this is merely one model of naturalistic evolution among a vast number, and the rest either say nothing about beliefs, or else contain false beliefs in the right combination with desires such that the right sort of behavior for natural selection is produced.  So, while that one particular model (the true-belief model) would provide for cognitive faculties reliably aimed at the truth, the rest would not; hence, the probability of naturalistic evolution producing reliable cognitive faculties is low or inscrutable, and this is the defeater for naturalistic evolution.	Consider now theism, and in particular the way in which Plantinga describes it.  According to Plantinga, theism avoids the defeater because it would provide for cognitive faculties reliably aimed at the truth.  But is this really true of theism?  One particular model of theism–the Christian model that Plantinga has in mind–certainly would provide for reliable cognitive faculties, given the nature of God taken together with our relationship to him.  But this is merely one model of theism among a vast number.  Indeed, we can easily and without much reflection imagine a vast number of theistic models that would not, in fact, produce reliable cognitive faculties.  I can imagine a God who loves us and is all-powerful but isn’t very knowledgeable or smart; I can imagine one who is all-powerful and all-knowing but who is indifferent towards us, like a scientist to a lab rat, or who perhaps even is somewhat sadistic; I can imagine polytheistic models with gods who couldn’t give us reliable faculties, perhaps because they have more important problems in the reaches of the universe to contend with, or else because they were in conflict with other gods; indeed, this list could continue for quite a long while.	The distinction with which I am here concerned lies in the use of the word ‘theism.’  As others have noted, the word has (at least) two meanings.  William Rowe, for instance, refers to ‘theism’ as having a narrow and broad sense.​[7]​  In the narrow sense, ‘theism’ means a particular belief in a particular God: that God who is omnipotent, omniscient, and omnibenevolent.  In the broad sense, however, ‘theist’ simply refers to someone who believes in one or some divine entity or entities.  Clearly, Plantinga means the word in the narrow sense​[8]​; here, then, it should be clear that the narrow sense is a sub-class of the broader sense.	What, though, does this mean for Plantinga?  All along, for Plantinga, theism has been safe from the defeater that served to undermine naturalistic evolution, precisely because theism could reasonably guarantee reliable cognitive faculties in a way that naturalistic evolution could not.  However, looking a little deeper, we can now see that, while this is true of the Christian model that Plantinga ultimately has in mind, it is not true for countless other theistic models.  Yet this now seems to be a clear parallel to the case of naturalistic evolution.  That is, there is at least one model of naturalistic evolution–the true-belief model described earlier–which would reasonably guarantee reliable cognitive faculties, just as there is at least one model of theism (Plantinga’s Christian model) which would offer the same reasonably secure guarantee.  Yet, the true-belief model is undermined by the preponderance of other naturalistic evolution models that would not provide for reliable cognitive faculties.  This, then, also applies to theism: Plantinga’s Christian model must be similarly undermined by the vast number of theistic models that also would not provide for reliable cognitive faculties.  Insofar as this counts as a defeater for naturalistic evolution, then, it surely must also count as a defeater for theism.	In light of this criticism, it is difficult to see how a defender of Plantinga might respond at this point.  It is true that he means to be speaking of one particular kind of theism, the narrow sense sketched earlier; he explicitly notes that he is following “…one particular and traditional way of thinking about our knowledge of Christian truth.”​[9]​  Yet, if it is true that this particular theistic model is immune from the defeater, it is also true that one particular model of naturalistic evolution (the true-belief model) is similarly immune.  Along these lines, then, insofar as Plantinga is concerned with one particular model of theism, he might shift the focus to one particular model of naturalistic evolution, rather than naturalistic evolution generally.  Yet this is problematic, for it is arbitrary.  It certainly is the case that the Christian model compares favorably to particular models of naturalistic evolution besides the true-belief model with regard to the defeater.  But it is unclear why the defender of naturalistic evolution must be pigeonholed in this way.  As Plantinga himself admits, naturalistic evolution need not appropriately account for reliable cognitive faculties; implicit in this observation is that, under some models, it very well might.  It is equally the case that theism need not account for reliable cognitive faculties.  To compare one of the few theistic models that gets it right, to one of the many naturalistic evolution models that doesn’t, unfairly and arbitrarily stacks the deck against the defender of naturalistic evolution.	Plantinga’s key flaw, then, ultimately lies in a faulty comparison.  The downfall of naturalistic evolution, for Plantinga, lies in the fact that naturalistic evolution suffers from a defeater that theism does not.  Yet this is only true when we compare naturalistic evolution generally to one particular model of theism.  Once we make this distinction, Plantinga’s argument collapses.  Both theism generally and naturalistic evolution generally suffer from this defeater, while particular models of each (namely, Plantinga’s Christian model and the true-belief model, respectively) do not.  In this context, the two models either stand or fall together, and so what counts as a defeater for one surely must for the other as well.  In light of this, Plantinga has two options: he must either accept that theism has the same defeater as naturalistic evolution, or else he must abandon his criteria and presentation of defeaters altogether.  To be sure, either option presents serious negative consequences for his project in general.PAGE  2^1	  A defense of the reliability of our cognitive faculties given naturalistic evolution has been compellingly pursued by several of Plantinga’s critics: Timothy O’Connor, “An Evolutionary Argument Against Naturalism?” Canadian Journal of Philosophy Vol. 24, No. 4 (1994) pp. 527-540.  Evan Fales, “Plantinga’s Case Against Naturalistic Epistemology,” Philosophy of Science 63 (1996) pp. 432-451.  Michael Levin, “Plantinga on Functions and the Theory of Evolution,” Australasian Journal of Philosophy Vol. 75, No. 1 (1997) pp. 83-98.  Branden Fitelson and Elliott Sober offer a similar criticism, arguing that Plantinga’s argument is question-begging; one will accept his defeater for naturalistic evolution, and the related security offered by theism, if one is already convinced beforehand that theism is likely true and naturalistic evolution is likely not true.  See “Plantinga’s Probability Arguments Against Evolutionary Naturalism,” Pacific Philosophical Quarterly 79 (1998) pp. 115-129.^2	  Anthony Peressini pursues precisely this line, that naturalistic evolution is not defeated by the low or inscrutable probability of our reliable faculties; see “Naturalism, Evolution, and Self-Defeat,” International Journal for Philosophy of Religion 44 (1998) pp. 41-51.  A different version of this response is offered by David Reiter, who argues by reductio that if Plantinga’s argument entails a defeater for naturalistic evolution, it must also entail something unacceptable: that perceptive naturalists have no prepositional knowledge.  See “Plantinga on the Epistemic Implications of Naturalism,” Journal of Philosophical Research Vol. XXV (2000) pp. 141-147.^3	  Others have argued that theism faces a defeater, but the defeater is a different sort of defeater than the one Plantinga offers regarding naturalistic evolution.  Richard Swinburne emphasizes biblical criticism and the problem of evil as potential defeaters for theism; see “Plantinga on Warrant,” Religious Studies 37 (2001) pp. 203-214.  Thomas McHugh Reed notes these same traditional problems for theism, and adds further that, if we are indeed the products of a perfect being, we also know that we sometimes form false beliefs; so, then, theism can offer no guarantees with respect to the reliability of our cognitive faculties.  See “Evolutionary Skepticism,” International Journal for Philosophy of Religion 42 (1997) pp. 79-96.^4	  Alvin Plantinga, Warranted Christian Belief (New York: Oxford University Press, 2000) 189.^5	  Ibid., 231.^6	  Ibid., 235.^7	  William Rowe, “The Problem of Evil and Some Varieties of Atheism,” American Philosophical Quarterly Vol. 16, No. 4 (1979) pp. 335-341.^8	  Indeed, Plantinga means something more specific than this, insofar as his understanding of theism not only speaks of God’s particular attributes, but also includes God’s creation of us in his image.^9	  Plantinga, 242.

Theism, Naturalistic Evolution and the Probability of Reliable Cognitive Faculties: A Response to Plantinga

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