«A DEFENSE OF ALVIN PLANTINGA’S EVOLUTIONARY ARGUMENT AGAINST NATURALISM A Dissertation presented to the Faculty of the Graduate School University ...»
A DEFENSE OF ALVIN PLANTINGA’S
EVOLUTIONARY ARGUMENT AGAINST NATURALISM
the Faculty of the Graduate School
University of Missouri-Columbia
In Partial Fulfillment
Of the Requirements for the Degree
Doctor of Philosophy
TROY M. NUNLEY
Dr. Jonathan Kvanvig, Dissertation Supervisor
Although there are many persons to whom I owe a debt of gratitude for their support, three stand out as those who made my journey in academics possible. I would like to thank my wife, Lily Chang, for her patience and support during the arduous process of completing this dissertation. I also wish to express my gratitude to my parents, Rev. John M. Nunley and Karen Nunley, for constantly encouraging and supporting me in my pursuit of a higher education.
A DEFENSE OF ALVIN PLANTINGA’S
EVOLUTIONARY ARGUMENT AGAINST NATURALISM
In this dissertation, I explicate and defend Plantinga’s attack on philosophical naturalism. My thesis is that it has survived all the current attacks available in the literature.
TABLE OF CONTENTSACKNOWLEDGEMENTS………………………………………………………………ii ABSTRACT…..………………………………………………………………………….iii Chapters
1. The Evolutionary Argument Against Naturalism………………………..1
A. IntroductionB. The Evolutionary Argument Ag
2. Initial Concerns Regarding Knowledge Laid to Rest…………………70 A. Presumptions with respect to the nature of justification B. Presumptions with respect to the nature of truth C. Presumptions with respect to the nature of belief
5. Defeat and the Crucial Analogy………………………………………205 A. The Charge of False Analogy B. Questions Regarding Exactly What a Successful Analogy Will Prove
6. The EAAN & Global Skepticism in General…………………………236 A. On the Possibility of Rationally Ignoring the EAAN B. Plodding Loops and the Possibility of Humean Defeat of R C. Partial vs. Total Defeat D. Attempted Reductions to Traditional Skepticism
7. Tu Quoques on Theism………………………………………………..275 A. Versions thereof B. Principles of Defeat and Uses Thereof C. New Attempts at Tu Quoques
8. Conclusion…………………………………………………………….315 BIBLIOGRAPHY……………………………………………………………….324 VITA………………………………………………………………………….....335 Chapter 1: The Evolutionary Argument A. Introduction Almost a decade ago in his book “Warrant and Proper Function” Alvin Plantinga first presented an argument intended to demonstrate that it was irrational to affirm both the neo-Darwinist account of human evolutionary history as well as the doctrine of philosophical naturalism. This argument has been updated in a later book, “Warranted Christian Belief,” and also received important emendations in a later compilation of essays, “Naturalism Defeated?” It is the purpose of this dissertation to give a comprehensive and critical analysis of all relevant literature pertaining directly to this argument. I take it as my thesis that the argument has successfully resisted all current attacks upon it in the literature and that consequently the theistic worldview enjoys stronger rational support than does its naturalistic contender.
For sake of clarity I must briefly mention exactly which evolutionary argument of Plantinga’s I will be referring to throughout this paper, for in point of fact he has two. The first is what he refers to as a “preliminary argument” and the second is his “main argument.” The preliminary argument is simply intended to demonstrate that the existence of our rational faculties is more likely given the truth of theism than it is given naturalism. Consequently the very existence of our rational faculties constitutes evidence for theism (given some Bayesian calculations) over its naturalistic rival. The main argument, to which most of the literature responding to Plantinga is addressed, reaches a more drastic conclusion.
In this dissertation, I will focus exclusively on Plantinga’s main argument and the replies thereto.
Interestingly, Plantinga is willing to concede that the preliminary argument that he makes in WPF is flawed, though not fatally. “This argument contains an error: it confuses the unconditional objective or logical probability of R with its probability conditional on our background knowledge.”1 In fact, Plantinga credits Fitelson and Sober, two of his harsher critics, for the insight. However, he also maintains that the preliminary argument has been repaired in the 2000 edition of WPF, on pp. 229-231.
In essence, the main argument claims that the naturalistic evolutionary processes widely assumed to have given rise the biological features of our species, and our cognitive machinery in particular, are processes one cannot reasonably believe likely to produce creatures with mostly true beliefs. Hence, if one accepts the naturalistic account of our evolutionary origins, agnosticism with respect to the reliability of our belief-forming mechanisms is in order. The most subtle portion of Plantinga’s argument, perhaps, comes next: if our cognitive machinery is held suspect in the fashion just described, then all of those beliefs which are formed in and through these faculties ought to be held suspect. For the evolutionary naturalist, one such belief that ought to be held suspect will be the belief in Plantinga, Alvin. “Probability and Defeaters.” Pacific Philosophical Quarterly, Vol. 84, 2003, 291-298, p. 291.
evolutionary naturalism itself. So, upon reflection at least, a belief evolutionary naturalism defeats itself. From this, Plantinga concludes that continued belief in the doctrines of evolutionary naturalism will be irrational. The doctrine is somehow self-defeating.
The foregoing paragraph gives the bare-bones outline of an argument which it is the purpose of this paper to scrutinize, criticize and ultimately defend. To do so will require not only a closer investigation of the argument itself but a defense
of each step of the argument. In particular, I take the key issues to be as follows:
1.) Is Plantinga correct with respect to his claim that naturalistic evolutionary processes are unlikely to give rise to reliable cognitive machinery? Is this defendable given the fact that creatures with a complex mental life exist (most notably, ourselves)? In Chapter 1, I explore Plantinga’s argument for this claim.
Chapter 3 of this dissertation is devoted to defending Plantinga’s claim against current attacks available in the literature.
2.) If Plantinga were correct with respect to his claim that naturalistic evolutionary processes are unlikely to bestow upon us reliable cognitive machinery, are there reasons to think that low probability in this case is insufficient to generate the defeat of our faith in our rational capacities? The low probability of a proposition being true can sometimes fail to generate a defeater for that proposition. For example, the proposition that I drew an ace out of a card deck last night on the first try has a low probability. But that fact alone does not prove that my belief that I had this fortunate recent draw is defeated or otherwise irrational for me to continue to hold. So the crucial question at this point is whether Plantinga’s demonstration that the probability of our cognitive mechanisms being reliable given evolutionary naturalism is low bears similarity to those cases in which low probability fails to generate a defeater for a belief.
Arguments against Plantinga on this point will be discussed in Chapter 4 “Probabilities and Defeat.” 3.) If Plantinga’s critics fail to make the case just described, there still will remain the question as to whether any positive argument exists for the conclusion that the case of the reflective evolutionary naturalist is one in which low (or at least inscrutable) probability does generate a defeater for a belief. Plantinga claims that the plight of the reflective evolutionary naturalist bears strong analogy to paradigm instances in which recognition or acceptance of such probability claims with respect to a belief defeat the belief in question. The argument for the strength of this analogy is present in my next section along with the explication of Plantinga’s overall argument. The extent to which Plantinga’s argument hinges on this analogy is large enough that some, notably Erik Wielenberg,2 have taken the argument as a whole to be an argument from analogy and this seems to me to be true. Hence, I will spend Chapter 5 “Defeat and the Crucial Analogy” defending Plantinga’s analogy.
4.) Plantinga’s argument has been thought of as an argument for global skepticism.
So far as the evolutionary naturalist is concerned, the conclusion of Plantinga’s Wielenberg, Erik J. “How to be an Alethically Rational Naturalist.” Synthese. 131, 2002, pp. 81-98.
argument might be even more disconcerting than Cartesian or Phyronnian skeptical arguments. For if we are to doubt the deliverances of our mental faculties to the extent that Plantinga suggests it could be the case that such propositions as “I exist” or “Modus ponens is a valid form of argument” might suffer defeat. At least one respondent to Plantinga’s argument, David Reiter, has rejected the argument simply because they see this as a reductio. Others, such as McHugh Reed and Nathan, have offered a more subtle form of this same objection. All of these will be examined in the course of this dissertation.
But global skeptical arguments have historically been met with forceful counterattacks and responses. Can the evolutionary naturalist appeal to one of these replies to global skepticism generally in order to make Plantinga’s argument look, if not unsound, at least uninteresting? If not, what is unique to Plantinga’s argument such that the evolutionary naturalist has a new skeptical issue with which to deal? This issue and the literature pertaining thereto will be explored in Chapter 6.
5.) On a related note, how is the theist, as opposed to the naturalist, spared this new source of epistemic grief? If an argument structurally similar to Plantinga’s can be advanced against the theist, it could at least be argued in a tu quoque fashion that the doctrine of evolutionary naturalism has not been shown more vulnerable to skeptical attack than the epistemic position of their theist opponents.
This would not be an ideal response to Plantinga’s argument, but it would give a measure of comfort to the evolutionary naturalist. Whether or not any such structurally similar skeptical argument threatens certain theistic beliefs will be taken up in Chapter 7, “Tu Quoques on Theism.” These are the key issues with respect to Plantinga’s argument as I see them.
Other issues of peripheral importance will be discussed, but the overwhelming majority of the literature and arguments contained therein can be directly related to one of these five areas of concern. All but two or three articles currently available in the literature (those of Lemos, Otte, Bielby and perhaps Alston) constitute attacks on Plantinga’s argument offered on the behalf of the evolutionary naturalist. Again, it is the thesis of this dissertation that those attacks have thus far met with no success.
B. The Evolutionary Argument against Naturalism
1. The Argument Explicated “Boiled down to essentials, a nervous system enables the organism to succeed in the four F’s: feeding, fleeing, fighting, and reproducing. The principle chore of nervous systems is to get the body parts where they should be in order that the organism may survive…. Improvements in sensorimotor control confer an evolutionary advantage: a fancier style of representing is advantageous so long as it is geared to the organism’s way of life and enhances the organism’s chances of survival (italics in original).
Truth, whatever that is, definitely takes the hindmost.” -Patricia Churchland3 “With me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey’s mind, if there are any convictions in such a mind?” –Charles Darwin4 The goal of Plantinga’s Evolutionary Argument Against Naturalism (henceforth, EAAN) is to take the popular doubts and concerns voiced in the quotes above, turn them into a positive argument, and then use them as ammunition against naturalist philosophy. So Plantinga’s first move is to give a formal presentation of what he calls “Darwin’s Doubt.” Let N stand for the thesis of naturalism. Whatever this entails, it should certainly entail that there is no God.
E will stand for the claim that contemporary evolutionary theory is true. The Quoted in all of Plantinga’s articles on the EAAN.
Plantinga, Alvin. “An Evolutionary Argument Against Naturalism.” Logos, Vol. 12, 1991, pp. 27-48.