Read Where the Conflict Really Lies: Science, Religion, and Naturalism Online
Authors: Alvin Plantinga
Tags: #Non-Fiction, #Biology, #Religious Studies, #Science, #Scientism, #Philosophy, #21st Century, #Philosophy of Religion, #Religion, #v.5, #Amazon.com, #Retail, #Philosophy of Science
The final premise of the argument is
(4) If one who accepts N&E thereby acquires a defeater for N&E, N&E is self-defeating and can’t rationally be accepted.
The entire argument, therefore, goes as follows:
(1) P(R/N&E) is low.
(2) Anyone who accepts (believes) N&E and sees that P(R/ N&E) is low has a defeater for R.
(3) Anyone who has a defeater for R has a defeater for any other belief she thinks she has, including N&E itself.
(4) If one who accepts N&E thereby acquires a defeater for N&E, N&E is self-defeating and can’t rationally be accepted. Conclusion: N&E can’t rationally be accepted.
This argument shows that if someone accepts N&E and sees that P(R/N&E) is low, then she have a defeater for N&E, a reason to reject it, a reason to doubt or be agnostic with respect to it.
Of course defeaters can themselves be defeated; so couldn’t you get a defeater for this defeater—a defeater-defeater? Maybe by doing some science—for example, determining by scientific means that her faculties really are reliable? Couldn’t she go to the MIT cognitive-reliability laboratory for a check-up?
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Clearly that won’t help. Obviously that course would
presuppose
that her faculties are reliable; she’d be relying on the accuracy of her faculties in believing that there is such a thing as MIT, that she has in fact consulted its scientists, that they have given her a clean bill of cognitive health, and so on. The great Scottish philosopher Thomas Reid put it like this:
If a man’s honesty were called into question, it would be ridiculous to refer to the man’s own word, whether he be honest or not. The same absurdity there is in attempting to prove, by any kind of reasoning, probable or demonstrative, that our reason is not
fallacious, since the very point in question is, whether reasoning may be trusted.
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Is there any sensible way at all in which she can argue for R? It is hard to see how. Any argument she might produce will have premises; these premises, she claims, give her good reason to believe R. But of course she has the very same defeater for each of those premises that she has for R, and she has the same defeater for the belief that if the premises of that argument are true, then so is the conclusion. So it looks as if this defeater can’t be defeated. Naturalistic evolution gives its adherents a reason for doubting that our beliefs are mostly true; chances are they are mostly mistaken. If so, it won’t help to
argue
that they can’t be mostly mistaken; for the very reason for mistrusting our cognitive faculties
generally
, will be a reason for mistrusting the faculties that produce belief in the goodness of that argument.
This defeater, therefore, can’t be defeated. Hence the devotee of N&E has an undefeated defeater for N&E. N&E, therefore, cannot rationally be accepted—at any rate by someone who is apprised of this argument and sees the connections between N&E and R.
VII TWO CONCLUDING COMMENTS
First, a comment on premise (2), according to which anyone who accepts (or believes) N&E and sees that P(R/N&E) is low, has a defeater for R. Now obviously the person who believes N&E also believes a lot of other propositions. Perhaps some of those other propositions are such that by virtue of her believing
them
she doesn’t get a defeater for R when she believes N&E. Perhaps she has a
defeater-deflector
for the looming defeat of R threatened by
P(R/N&E) is low
and N&E. This could happen if, for example, there were some proposition X she also
believes, such that P(R/N&E&X) is not low. Here’s an example of a defeater-deflector. Go back to the sheep in the field example of a few paragraphs back. I see what I take to be a sheep in the field: the farmer who owns the field comes along and tells me that there are no sheep in that field, but adds that he has a sheep dog who looks like a sheep from this distance. That gives me a defeater. But suppose the farmer’s wife had told me earlier on that her husband has developed a thing about sheep and sheep dogs, and tells everyone that there are no sheep in the field, even though there often are. Her telling me this is a
defeaterdeflector
: because I believe what she says, the farmer’s comments about sheep and sheep dogs don’t give me a defeater for my belief that I see a sheep—a defeater the owner’s remarks would otherwise would have given me.
Returning to N&E and R, is there a defeater deflector for the defeat of R threatened by N&E and P(R/N&E) is low? Is there a belief X the naturalist might have such that P(R/N&E&X) is not low? Well, it certainly looks as if there are: what about R itself? That’s presumably something the naturalist believes. P(R/N&E&R) is certainly not low; it’s 1. But of course R itself isn’t a proper candidate for being a defeater-deflector here. If a belief A could
itself
be a defeater-deflector for a putative defeater of A, no belief could ever be defeated.
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Which beliefs are such that they can properly function as defeater-deflectors? Which beliefs are admissible in this context—that is, which beliefs X are such that if P(R/N&E&X) is not low, then X is a defeater-deflector for R and N&E and P(R/N&E) is low? This is the
conditionalization problem
.
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It isn’t easy to give a complete answer, but we can say at least the following.
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First, neither R itself nor any proposition equivalent to it—for example,
(R v (2+1=4)) & ~(2+1=4)—
is admissible as a defeater-deflector here. Second, conjunctions of R with other propositions
P
the naturalist believes—for example,
(2+1=3) & R—
will not be defeater-deflectors, unless
P
itself is; more generally, propositions
P
that entail R will not be defeater-deflectors, unless a result of deleting R from
P
is a defeater-deflector.
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Finally, no proposition
P
that is evidentially
dependent upon R for
S
—that is, such that
S
believes
P
only on the evidential basis of R—is a defeater-deflector for R. Thus
either R or naturalism is true
, is evidentially dependent, for me, upon R (since I believe naturalism is false), as is
either R or Friesland is larger than the United States
, and
there is some true proposition P such that P(R/N&P) is high
. There is much more to be said, but instead of saying it here, I will refer the interested reader to my paper “Content and Natural Selection.”
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Second final comment: there is a slightly different version of this argument that has somewhat weaker premises; some might find that version appealing on that account.
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The argument as I presented it above has as a premise that P(R/N&E) is low: it is unlikely that our cognitive faculties are reliable, given naturalism and the proposition that we and those faculties have come to be by way of evolution. Here we are speaking of
all
of our cognitive faculties. But perhaps there are interesting distinctions to be made among them. Perhaps some are less likely than others to be reliable, given N&E. Perhaps those faculties that produce beliefs that appear to be relevant to survival and reproduction are more likely to be reliable than those faculties that produce beliefs of other kinds. For example, one might think that perceptual beliefs are often more likely to be relevant to adaptive behavior than beliefs about, say, art criticism, or postmodernism, or string theory. So consider
metaphysical
beliefs—for example, beliefs about the ultimate nature of our world, about whether there are both concrete and abstract objects, about the nature of abstract objects (if any), and about whether
there is such a person as God. Metaphysical beliefs don’t seem to be relevant to survival and reproduction. And of course naturalism is just such a metaphysical belief. This belief doesn’t seem relevant to survival and reproduction: it is only the occasional member of the Young Atheist’s Club whose reproductive prospects are enhanced by holding the belief that naturalism is true.
So consider the faculty (or subfaculty), whatever it is, that produces metaphysical beliefs, and call it “M.” And now we can ask the following question: given N&E, what is the probability that M is reliable? What is P(MR/N&E), where MR is the proposition that metaphysical beliefs are reliably produced and are mostly true? Some people may think this probability is clearly low, even if they aren’t so sure about P(R/N&E). If that’s how you think about the matter, I propose that you replace the first premise of the argument by
(1*) P(MR/N&E) is low;
everything else can go on as before.
It is time to bring this chapter and indeed this book to a close. I argued in the earlier portions of the book that there are areas of conflict between theism and science (evolutionary psychology for example), but that the conflict is merely superficial. I went on to argue in
chapter 9
that there is deep concord between science and theistic belief; science fits much better with theism than with naturalism. Turning to naturalism, clearly there is superficial concord between science and naturalism—if only because so many naturalists trumpet the claim that science as a pillar in the temple of naturalism. As I argue in this chapter, they are mistaken: one can’t rationally accept both naturalism and current evolutionary theory; that combination of beliefs is self-defeating. But then there is a deep conflict between naturalism and one of the most important claims of current science. My conclusion, therefore, is that there is
superficial conflict but deep concord between science and theistic belief, but superficial concord and deep conflict between science and naturalism. Given that naturalism is at least a quasi-religion, there is indeed a science/religion conflict, all right, but it is not between science and theistic religion: it is between science and naturalism. That’s where the conflict really lies.
A priori
insight, 6, 45, 149, 156, 178, 179, 233, 270, 301–302, 312
A posteriori
knowledge, 301–302
Abraham, William, 45n
Abstract objects, 212, 288–291
as divine thoughts, 288–291, 348
Adams, Robert, 42, 43
Adaptive behavior, 151, 271, 327, 331, 334, 348
Adequatio intellectus ad rem
, 269, 296, 299
Agency detection, 141, 246n.
See also
HADD
Alberts, Bruce, 232, 234
Allegro, John, 157
Alston, William, 43, 45n, 46n, 48, 78n, 249n
Altruism, 134–136, 163, 164, 173
Ames, William, 275
Anthropic principle, 199–203
Ancient earth thesis, 8, 10, 11, 55–56, 144n
Aquinas, Thomas, 4, 5, 43, 60, 67, 68, 108, 135, 136, 152, 154, 178, 181, 237, 268, 269, 273, 274, 288 302n, 312, 313, 337
Aristotle, 292, 293, 294, 299, 302n, 319
Armstrong, David, 279, 280
Atkins, Peter, 75, 229n
Atran, Scott, 138, 139, 140, 143, 145, 182–183
Atheism, ix–xi, 30, 53, 142, 199, 214, 220, 223, 282
Atonement, 46, 59, 155, 164, 173, 262
Augustine, 10, 55, 89, 149, 154, 273, 318
Austin, J.L., 313
Ayala, Francisco, 254n
Barbour, John, 97
Barrow, John, 196
Barrett, Justin, 60n, 138, 140n, 141n
Basic belief, 42–49, 188, 241–247, 249–251, 270, 341–342
Bayes’ theorem, 197n, 219–223, 240
Behe, Michael, 225–236, 237, 257–258, 262–264
Belief, xiv, 42–49, 60–62, 122–124, 137–143, 145–152, 163–168, 171–178, 178–183, 183–190, 240–244, 249–252, 260–262, 292–295, 309–350
basic.
See
basic belief
content, 321–325, 327–331, 333–339, 348n
Belief forming process/mechanism, xiv, 42–49, 137–143, 145–152, 178–183, 240–244, 249–252, 292–295, 309–350
Benacerraf, Paul, 291n
Bergmann, Michael, 167n, 340n
Bering, Jesse, 140n
Berry, Michael, 85n
Bertrand paradoxes, 332
Big Bang, 35, 121, 195–196, 212–213, 293
Big Crunch, 212–213
Bodin, Jean, 61
Bohr, Niels, 123
Boyer, Pascal, 138–140, 145
Boyle, Robert, 266, 275–276
Brading, Katherine, 95
Broadly inductive procedures, 270.
See also
induction
Brooke, John, 6n
Brown, Raymond, 155–156
Bultmann, Rudolph, 70–74, 76, 90, 96, 102n, 105, 158–159
Calvin, John, 60, 68, 108, 145–146, 152, 154, 178–179, 181, 263, 312
Calvinism, 145–152, 171