This is Part 3 in a 3 part series on evolutionary theories of cognition. This part discusses Alvin Plantinga’s Evolutionary Argument Against Naturalism. Part 1 examined C.S. Lewis’ Argument from Reason and part 2 covered Plantinga’s Argument from Proper Function. See Part 1 of this article here and Part 2 here.
Alvin Plantinga’s Evolutionary Argument Against Naturalism
Plantinga also formulated an “Evolutionary Argument Against Naturalism” as follows:
(15) If both naturalism and evolution are true, then human cognitive faculties are the result of blind mechanisms such as natural selection.44
(16) Natural selection selects for survival-related behaviors, not necessarily true beliefs (except to the extent belief is “appropriately related to behavior”).45
(17) If evolutionary naturalism is true, then the primary function of human cognitive abilities is to promote survival-related behaviors, not necessarily the production of true beliefs.46
(18) Given that it is not natural selection’s primary function, the probability of evolutionary naturalism producing cognitive faculties that lead to true beliefs is low or inscrutable.47
(19) One of the allegedly true beliefs held by the naturalist is a belief in metaphysical naturalism itself.48
(20) Therefore, “the devotee of [evolutionary naturalism] has a defeater for any belief he holds, and a stronger defeater for [evolutionary naturalism] itself.”49
Plantinga’s second argument has more in common with Lewis than his first. While they take slightly different paths, both arguments demonstrate that if human cognitive reasoning is the result of evolutionary naturalism, it cannot be trusted to yield truth. Because of their commonalities, similar objections are advanced to both.
One such objection is launched at (16) and (17). Plantinga and Lewis both assume an either/or proposition; i.e., either natural selection favors survival or it favors truth. Critics claim that the two go hand in hand, with the generation of true beliefs promoting survival and fitness.50 Plantinga responds by explaining that the probability of an evolutionary process producing true beliefs is low or inscrutable.
Survival depends upon behavior, not beliefs. An organism can believe that something will promote its survival, but unless it actually behaves in an adaptive manner it will not survive. The criticism, therefore, is only sound if true beliefs lead to adaptive behavior. Plantinga lays out five possibilities:
(i) There may be no connection between beliefs and behavior.51
(ii) Beliefs may be the effects, rather than the cause of behavior.52
(iii) Beliefs may be causally related to behavior via their syntax, not their content (as someone’s voice may break glass due to the sound itself, not the words being sung).53
(iv) Beliefs may be causally related to behavior both syntactically and semantically, but maladaptive.54
(v) Beliefs may be causally related to behavior and adaptive.55
The last possibility is that advanced by naturalists. On any of the other four, natural selection would not necessarily produce true beliefs. Even under (v) it is still improbable that beliefs are true. This is because beliefs do not causally produce behavior by themselves; it is beliefs, desires, and other things that do so together. Suppose we oversimplify a bit and say that my behavior is a causal product of just my beliefs and desires. Then the problem is that clearly there will be any number of different patterns of belief and desire that would issue in the same action; and among those there will be many in which the beliefs are wildly false.56
Taking into account all possibilities, the probability of evolution producing an accurate belief forming mechanism is low or inscrutable.
In response, William Alston suggests that even if belief in evolutionary naturalism casts doubt upon reliable rationality, the great deal of basic warrant enjoyed by the latter will vastly outweigh any defeating tendency of the former.57 But Alston misconstrues the nature of a defeater. Defeaterhood “has to do with what the design plan requires, once you acquire a new belief; it does not have to do with the rationality, for you, of this new belief.”58 There is no calculus of warrants. If you hold belief a (regardless of whether a itself is rational), it becomes irrational for you to simultaneously hold belief b if one of the entailments of a is that b is not true.
[G]iven that I believe that my head is made of glass, what changes in my noetic structure are required by proper function? Well, one thing that will occur (if the defeater system is functioning properly), is that I will no longer believe that my head is made of flesh and bone.59
Similarly, given that a person believes in evolutionary naturalism, the entailments of that belief invalidate any acceptance of reliable rationality.60 Relative “weights” are irrelevant. The issue is one of internal consistency within a worldview.61
Conclusion
Naturalistic phenomena are related to each other only on a cause-effect basis. Human reasoning abilities must have a “proper function.” The survival-related behaviors preferred by natural selection are unlikely to be associated with true belief forming mechanisms. As C.S. Lewis and Alvin Plantinga demonstrate, any of these factors, when taken to their logical conclusion, demonstrate the irrationality of a worldview based upon evolutionary naturalism.
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44. Plantinga, Warrant and Proper Function, 219.href=”#ref44″>↩
45. Plantinga, Warrant and Proper Function, 219. Alvin Plantinga, “Introduction,” in Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism, ed. James Beilby (Ithaca: Cornell University Press, 2002), 4.href=”#ref45″>↩
46. This is derived from (15) and (16).href=”#ref46″>↩
47. Plantinga, Warrant and Proper Function, 219.href=”#ref47″>↩
48. Plantinga, Warrant and Proper Function, 231.href=”#ref48″>↩
49. Plantinga, Warrant and Proper Function, 233. Plantinga explains the notion of a “defeater” as follows: “A defeater for a belief b, then, is another belief dsuch that, given my noetic structure, I cannot rationally hold b, given that I believe d.” Alvin Plantinga, Warranted Christian Belief (New York: Oxford University Press, 2000), 361.href=”#ref49″>↩
50. Some responses to this position were previously discussed under the heading on Lewis’ Argument from Reason.href=”#ref50″>↩
51. Plantinga, Warrant and Proper Function, 223; Alvin Plantinga, “Naturalism Defeated,” paper dated 1994, http://philofreligion.homestead.com/files/alspaper.htm (accessed March 31, 2011).href=”#ref51″>↩
52. Plantinga, Warrant and Proper Function, 223-24; Plantinga, “Naturalism Defeated.”href=”#ref52″>↩
53. Plantinga, Warrant and Proper Function, 224; Plantinga, “Naturalism Defeated.”href=”#ref53″>↩
54. Plantinga, Warrant and Proper Function, 224; Plantinga, “Naturalism Defeated.”href=”#ref54″>↩
55. Plantinga, Warrant and Proper Function, 224; Plantinga, “Naturalism Defeated.”href=”#ref55″>↩
56. Plantinga, Warrant and Proper Function, 225 (emphasis in original).href=”#ref56″>↩
57. William Alston, “Plantinga, Naturalism, and Defeat,” in Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism, ed. James Beilby (Ithaca: Cornell University Press, 2002), 200.href=”#ref57″>↩
58. Plantinga, “Reply to Beilby’s Cohorts,” 274.href=”#ref58″>↩
59. Plantinga, “Reply to Beilby’s Cohorts,” 275.href=”#ref59″>↩
60. Many other critics of Plantinga make this same logical error; failing to recognize that their reasoning brings them around in a circle and they must assume the reliability of rationality in order to prove anything (including naturalism itself). Ernest Sosa, for example, claims that the senses give people “reliable access” to their surrounding world and on that basis they can perceive truth, all the while failing to realize that whether people can in fact have “reliable access” is the very issue up for discussion. Ernest Sosa, “Natural Theology and Natural Atheology: Plantinga’s Evolutionary Argument Against Naturalism,” in Alvin Plantinga, ed. Deane-Peter Baker (Cambridge: Cambridge University Press, 2007), 97.href=”#ref60″>↩
61. William Alston also questions Plantinga’s conclusion that the assumption of reliable rationality gives the naturalist a defeater for evolutionary naturalism as opposed to the reverse; perhaps evolutionary naturalism provides a defeater for reliable rationality and it is the assumption of reliable rationality that should be abandoned. Alston, “Plantinga, Naturalism, and Defeat,” 186. Of course, someone who abandons the assumption of reliable rationality as Alston suggests “acquires a defeater for all that she believes, including, of course [evolutionary naturalism], so that once again rationality requires that she give up [evolutionary naturalism].”Plantinga, “Reply to Beilby’s Cohorts,” 273. Either way, naturalism must be abandoned.href=”#ref61″>↩
BIBLIOGRAPHY
Alston, William. “Plantinga, Naturalism, and Defeat.” In Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism. Edited by James Beilby, 176-203. Ithaca: Cornell University Press, 2002.
Beversluis, John. C.S. Lewis and the Search for Rational Religion. Amherst, NY: Prometheus, 2007.
Bigelow, John and Robert Pargetter. “Functions.” The Journal of Philosophy 84, no. 4 (April, 1987): 181-96.
Drange, Theodore. “Several Unsuccessful Formulations of the Argument from Reason: A Response to Victor Reppert.” Philosophia Christi 5, no. 1 (2003): 35-52.
Lewis, C.S. “Miracles.” In The Complete C.S. Lewis Signature Classics. Edited by Joseph Rutt, 205-309. San Francisco: HarperCollins, 2002.
McGinn, Colin. The Mysterious Flame: Conscious Minds in a Material World. New York: Basic Books, 1999.
Mirza, Omar. “The Evolutionary Argument Against Naturalism.” Philosophy Compass6, no. 1 (2011): 78-89.
O’Connor, Timothy. “A House Divided Against Itself Cannot Stand.” In Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism. Edited by James Beilby, 129-34. Ithaca: Cornell University Press, 2002.
Plantinga, Alvin. “Introduction.” In Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism. Edited by James Beilby, 1-12. Ithaca: Cornell University Press, 2002.
—.“Is Belief in God Rationally Acceptable?” In Philosophy of Religion: A Reader and Guide. Edited by William Lane Craig, 40-56. New Brunswick, NJ: Rutgers University Press, 2002.
—.Naturalism Defeated. Paper dated 1994. http://philofreligion.homestead.com/files/alspaper.htm (accessed March 31, 2011).
—.“Reply to Beilby’s Cohorts.” In Naturalism Defeated? Essays on Plantinga’s Evolutionary Argument Against Naturalism. Edited by James Beilby, 204-75. Ithaca: Cornell University Press, 2002.
—.Warrant and Proper Function. New York: Oxford University Press, 1993.
—.Warrant: The Current Debate. New York: Oxford University Press, 1993.
—.Warranted Christian Belief. New York: Oxford University Press, 2000.
Reppert, Victor. C.S. Lewis’s Dangerous Idea: A Philosophical Defense of Lewis’s Argument From Reason. Downers Grove, IL: IVP Academic, 2003.
Sosa, Ernest. “Natural Theology and Naturalist Atheology: Plantinga’s Evolutionary Argument Against Naturalism.” InAlvin Plantinga. Edited by Deane-Peter Baker, 93-106. Cambridge: Cambridge University Press, 2007.
Wielenberg, Erik J. God and the Reach of Reason: C.S. Lewis, David Hume, and Bertrand Russell. Cambridge: Cambridge University Press, 2008.
—.“How to Be an Alethically Rational Naturalist.” Synthese 131, no. 1 (April 2002): 81-98.
” . . . the probability of evolutionary naturalism producing cognitive faculties that lead to true beliefs is low . . . ”
and then
” . . . if human cognitive reasoning is the result of evolutionary naturalism, it cannot be trusted to yield truth . . . ”
Straw man fallacy, yes? I’m sure I’m not the only one noticed this one.
A little advice. Proof read, then proof read again for logical fallacies. Most of us commit them at least some of the time. Perhaps due to “the probability of evolutionary naturalism producing cognitive faculties that lead to true beliefs is low.”
I would certainly agree with this statement when taking into account the absurd things many folks believe to be absolutely true (i.e. 2000 year old zombies)
The real issue with scientist and philosophers alike (I am both) is an unwillingness to be truly honest with one’s epistemology.
In other words, most scientists and philosophers are entirely too sure of their own personal world view. Most folks working in these fields are so ingrained in the pervasive frame work of thought inherent to their training that they fail to see how other groups accumulate, process, and apply knowledge.
Oh yeah, that’s right, I seem to be talking about epistemology. I really can’t reiterate it enough here you critical thinkers of the world. Epistemology, epistemology, epistemology.
It is not what you “know,” is it the manner in which you came to that knowledge which must be examined.
“Plantinga responds by explaining that the probability of an evolutionary process producing true beliefs is low or inscrutable.”
Thereby revealing his infinite out-to-lunchness.
“Taking into account every possible shape water can be in, what are the ‘chances’ the puddle just happens to be in the same shape as the hole in the ground?”
That is what it feels like to argue against Plantinga.
“(iv) Beliefs may be causally related to behavior both syntactically and semantically, but maladaptive.”
But not consistently, over time, which is the scale on which selection operates.
(v) Beliefs may be causally related to behavior and adaptive.”
You think?
Even under (v) it is still improbable that beliefs are true. This is because beliefs do not causally produce behavior by themselves; it is beliefs, desires, and other things that do so together.
Incorrect. Beliefs are behavior. More precisely, a belief just is the set of consequences of behavior delimited by anticipations of future experience.
Given two otherwise identical thirsty organisms A and B differing only in the belief that the oasis is East or the oasis is West, the property of “believing the water is thataway” just is which way they can be expected to start walking.
Which leads to the following Very Deep Point. (When you woke up this morning, you probably didn’t know you were going to learn a Very Deep Point, so hey, what a great day, right?)
In what sense could a belief which systematically generates accurate parsimonious predictions of experience be meaningfully said to be “false”?
“Suppose we oversimplify a bit and say that my behavior is a causal product of just my beliefs and desires. Then the problem is that clearly there will be any number of different patterns of belief and desire that would issue in the same action; and among those there will be many in which the beliefs are wildly false.56
Taking into account all possibilities, the probability of evolution producing an accurate belief forming mechanism is low or inscrutable.
A flat probability distribution. Assumed without argument. How droll.
Once again, the apologist Retreats To The Possible. Anything’s possible. The real question is, what’s likely.
As my favorite poster said once, “Sure, you can fluke a tiger-footrace once in a blue moon. But will that kind of brain really get your genes through to the next generation?”
Clearly not, but as his execrable tiger-footrace intuition pump demonstrates, it’s never really occurred to him to acquire clue the first about how actual biology works, so he talks about individual beliefs (for which genes do not code) and imagines he’s said anything relevant about the genes that code for belief-forming systems. As complicated as the human brain already is, he thinks evolution could tolerate the parsimony cost of an entire extra system which systematically creates an alternate universe of semantic content infinitely isolated from experiential correction?
Its hard to add to what staircase has already succinctly addressed. Well done. The oasis example really explains it all.