Thursday, December 8, 2011
Classical Global Skepticism and the EAAN
Update (Sep. 12, 2015): I'm temporarily taking this post offline -- like for a year or so -- because it inspired me to write a more detailed article that is being published in an academic journal. Even though a blogpost doesn't (or at least shouldn't) count as a prior publication of something, and even though the article and blogpost are only similar in very broad strokes, I'd like to avoid any appearance of impropriety.
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Alvin Plantinga,
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Philosophers,
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9 comments:
Excellent post. You have obviously read a lot more on epistemology than I have. One thing that I don't understand is your refutation of Descartes. The evil genie can't trick you into thinking that you are thinking when your really not because both your thinking and your existence are prerequisites for being tricked. Thus the cognito.
I agree with you that the EAAN can't be treated like global skepticism because it is specifically targeted at the combination of naturalism and evolution. Take one of those away and you've resolved the problem. Also, naturalism is really a metaphysical philosophical theory so it would be more threatened by the EAAN than any other more basic beliefs or really most beliefs about science or how the world works.
The problem with this is that my existence is presented as the conclusion of an argument. If the evil genie is tricking me, then I must exist (there must be someone he's tricking). But the whole point of the evil genie is that we can't trust conclusions of arguments, even deductive (a priori) arguments. All "if ... then" arguments are called into question.
One partial solution is to reject treating one's own existence as the conclusion of an argument. Descartes sets the whole thing up so we can only affirm our own existence via argument and that's simply not why we believe that we exist. Rather, we should treat it as something simply given. We don't have to have a reason for believing that we exist. I think that part of Plantinga's epistemology is right on the money. This doesn't entirely avoid the evil genie scenario (although a lot of epistemologists think the genie can't apply to a priori knowledge at all), but it certainly avoids it at one level.
Ah, I think I'm tracking with you.
Btw, I'm reading Dallas Willard now and am enjoying it. I checked out his book, Knowing Christ Today" from a recommendation on your blog. I love how fluidly he writes. Whether the book is truly good or not however will depend upon whether he can deliver on his claim that Christianity is knowledge rather than just faith or commitment. I think that is a tough bar to meet for anyone so I'll see how that goes.
The best modern psychological research basically confirms the important parts of the EAAN: our reasoning is fallible, our perceptions are subject to physiological, neurological, and psychological errors. In many ways, our brains work just the same way as our evolutionary cousins - other apes, other mammals, etc.
But just because a machine is fallible does not make it useless. A Bayesian approach to reasoning and belief is still valid, even once we acknowledge that all of the bases of our beliefs are imperfect.
Actually, it seems to me that something very like Plantinga's concept of "warranted belief" can be used to rescue naturalism from the problem he thinks he has discovered. If it is the case that evolution would favour organisms whose beliefs are true over those whose beliefs are false, then we are warranted in accepting our beliefs even knowing that they are constrained by our evolutionary history.
Well, Timothy, people have always known that our cognitive abilities are fallible and can be impacted by physiological issues. The first person who ever got drunk figured that out. The debate over fallibilism in epistemology is not about whether we are fallible but whether knowledge is fallible. If it is, then it would be possible to know something that is false, which seems to be a contradiction. But if we hold it up to that standard then we can't be certain of anything.
At any rate, you're missing the challenge of the EAAN. Classical global skepticism played on the fact that our knowledge is not 100%. The EAAN claims that if naturalism is true any particular belief one selects has a 50% chance or less of being correct. In other words, you have a defeater for that belief, a reason for withholding belief in that proposition. You can't defend that belief by giving an argument for it, because the belief that the argument is successful itself has only a 50% chance or less of being true. In other other words, it is irrational to believe anything. It's not merely a matter of being fallible but of being unreliable. Of course the argument may fail, but that's what it claims to show. In order to avoid it one has to reject naturalism.
Jim, thanks for the clarifications.
I suppose this is why I'm not a philosopher. My main interest is in whether my beliefs (or people's beliefs in general) are fallible - and to what extent, and in what circumstances. The question of whether "knowledge" is fallible seems to balance rather precariously on the definition of the term "knowledge". I recognize this is not a trivial question, but I feel that some intuitive correspondence theory version is probably good enough for most discussions.
Reading over the EAAN link you gave, it seems to me that part of the disagreement here may be a matter of definition. Plantinga makes much of the fact that beliefs may be causally unconnected to behaviour, and thus invisible to natural selection. Fine, but then they are less interesting. I know that sounds like a dodge. On the other hand, it seems strange that Plantinga is talking about "reliable" and "unreliable" beliefs, while explicitly disavowing the necessity of a causal connection between beliefs and behaviours. Surely a "reliable" belief would be one that, if it were used to drive behaviour, could be generally relied on to produce a desired result.
I think I'd want to see a good solid definition of "knowledge" or "belief" before accepting his criticism that beliefs may correspond only syntactically rather than semantically to the truth. What is the important distinction between these two? What makes a proposition syntactically "true" but semantically "false"? (I'm not trying to be cheeky here - as a linguist, I recognize that there may be an important distinction here, but I don't know what the philosophical definitions are that Plantinga is using.)
I appreciate his calculation of probabilities, but I just don't find his estimates of the probabilities to be particularly compelling (as he seems to anticipate).
Finally, setting aside the (to me uninteresting) causally unconnected beliefs, I think my comment about evolution producing "warranted beliefs" may still apply. Of course, knowing how evolution works, we would only be warranted to provisionally accept any particular belief. But I would submit that, knowing human fallibility, the same could be said of warranted Christian belief.
This is where I don't get philosophers. The whole argument is based on an "if x, then y" construction (as best I understand it). But it only takes a cursory examination of the argument to realise Plantinga's "x" hinges on a failure to understand basic biology.
What I fail to grasp is why anyone cares? Plantinga erects and defeats a strawman. His argument may be interesting, but since the caricature he defeats is based only on his misunderstanding or misrepresentation of basic biology.
While I understand that the structure of the argument may be interesting to philosophers, the conclusions lack any validity. So it baffles me that people continue to discuss the implications of the conclusions.
Ian, Plantinga's claim is philosophical, not biological. Even the most naturalized of naturalized philosophers will still insist that what they're doing is philosophy, not science. You can certainly point out that, insofar as they are relying on science, that the science has to be valid. But then I don't see what basic biological facts Plantinga's philosophy contradicts.
At any rate, my point in this post is not to defend his argument but simply to show the similarities and differences between it and traditional global skepticism.
Hi, very nice analysis.
the problem I find with Plantinga's argument is its kind of circularity.
suppose that I am a naturalist. Now why I should believe that I have a defeater for R? Isn't it because of accepting the first premise of EAAN, i.e. "P(R/N+E) is low"? Of course it is. So in order to accept the second premise, I, the naturalist, must BELIEVE that the first premise (I will call it Q, hereafter) is true. Q is one of my beliefs which is produced by my cognitive faculties, and if I have a defeater for R, then I will have a defeater not only for N+E, but also for Q; and this makes the argument problematic. Plantinga supervenes the truth of Q over N+E, though he does not have any good reason to do so while the cognitive reliability is the subject of discussion. We can call this error "non-reasonable truth supervention".
If I have enough evidence for natural selection, then I can arbitrarily comprise "evolutionary argument against professor Plantinga":
1) N&E
2) Anyone who accepts (believes) "P(R/ N&E) is low" and sees that N&E are true 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 "P(R/ N&E) is low" itself.
4) If one who accepts "P(R/ N&E) is low", thereby acquires a defeater for "P(R/ N&E) is low" , "P(R/ N&E) is low" is self-defeating and can’t rationally be accepted. Conclusion: "P(R/ N&E) is low" can’t rationally be accepted.
What if naturalism will be proved by evidence? Then how would we act? deny it, for the sake of an analytic argument?
the problem is with the form of argument which ultimately leads to self referring propositions like
I am truthful or I am liar.
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