Monday, December 12, 2005

Book Review: C.S. Lewis's Dangerous Idea

Originally uploaded by Phil Steiger.
Victor Reppert’s book, C.S. Lewis’s Dangerous Idea: In Defense of the Argument from Reason, is a relatively short, but philosophically rigorous book. The fundamental burden of the book is to explicate Lewis’s argument found in his Miracles, sometime called the argument from reason, and defend it against some contemporary trends in philosophy. Reppert takes an almost deceptively simple argument against naturalism and reveals it as the powerful apologetic tool that it is.

Lewis’s fundamental claim is that rational inference cannot be explained in purely naturalistic terms, and because it is obvious that rational inference does occur, that is a reason to reject naturalism. The title of the book is a self-confessed spin-off of Dennett’s book, Darwin’s Dangerous Idea. The deliberate connection in the title juxtaposes Dennett’s contention about the fundamental realities of reasoning and Lewis’s. Dennett argued that the best way to build knowledge was through the use of “cranes” and not “skyhooks.” Cranes are ideas and theories built on previous, naturalistically achieved, theories. A skyhook is a derogatory term for theories explained in terms of the supernatural or non-natural, and which, as the title implies, have no real grounding. Lewis’s contention is that there is something fundamental about the way reason works that turns Dennett’s idea on its head.

The first obstacle Reppert works to overcome is what he calls a biographical objection. He notes that many of the objections to Lewis’s philosophy are attacks on Lewis the person and not on his ideas. As legend has it, this argument of Lewis’s was once attacked and (apparently) trounced at a meeting by Elizabeth Anscombe. As the legend goes, Lewis basically gave up his apologetic writings after this apparent embarrassment. But as Reppert details, Lewis not only replied to Anscombe’s objections in an updated version of Miracles, Anscombe openly admitted that the second version was much more rigorous and harder to critique.

This section of the book was helpful to me in that I think many people’s objection to Lewis as a serious philosopher are biographical and not technical. His reputation as a favorite of evangelicals and as the author of children’s books has colored the view of many. In all honesty, I don’t see the need for the seeming bifurcation between serious thinker, religious thinker, and popular author. I think we need more serious and rigorous thinkers, not less, writing popular books than we might have now.

After a helpful chapter on apologetic arguments in which Reppert classifies Lewis as a “critical rationalist,” the philosophical defense begins in ernest. The first objections he deals with are the original objections posited by Anscombe. She critiqued Lewis’s original formulation by arguing that non-rational reasons may give rise to rational inference (Lewis originally used the term “irrational”), and that paradigm cases of reasoning may serve as an example of good and bad rational inference. Later in the book, Reppert continues to defend the argument from reason against more contemporary objectors. He deals with critiques concerning the explanatory power of non-physical causes, and what he calls the inadequacy objection.

Essentially, the inadequacy objection is that when naturalistic/materialistic reasons are found for any explanatory gap, they are the best and most sufficient explanations for phenomena. So, non-physical explanations, by their very nature, fall short. This chapter, along with its specific intent, provides a solid philosophical look into an answer to the “god-of-the-gaps” objection to theism.

Theism, and all the science and philosophy surrounding it, is often rejected as a point of view that will naturally be discarded when a better, materialistic, explanation is discovered. So is the case in this book with rational inference. Lewis and Reppert argue that it cannot be explained by naturalism, and thus is a reason to reject it. Naturalists reply that the non-natural explanation is a stopgap measure that will simply fade away when science has caught up with itself: we used to explain thunder as God doing something or other in the heavens, and now we know differently. It is, so the argument goes, the same with rational inference.

But Reppert’s point is that the argument from reason is no “god-of-the-gaps” argument. Instead of being an argument simply from an ignorance of natural explanation, it is a positive argument about the only good philosophical explanation for rational inference. In other words, if the argument from reason holds, there is logically no naturalistic explanation for the exercise of reason.

This same point can be made in the case of Intelligent Design, and recent work in the area of testable models of nature that infer (or abduct, if “abduct” is a verb) the existence of an intelligence. The straw man argument against ID is the claim that it is a “god-of-the-gaps” point of view that will disappear with the next scientific advancement. But that misses the point entirely. The point is the same as Reppert’s-if the argument holds, naturalism will never explain our origins or our apparent design.

I would highly recommend this book with one simple caveat: be prepared to think. It was a more philosophically rigorous book than I expected. I refuse to call this caveat a warning: it is a challenge and an encouragement to think a bit more deeply about Lewis, about apologetics, and about how your mental faculties work.


Weekend Fisher said...

Could you give any insights on the differences between the first version of Lewis' argument and the second? I've seen a version of it (don't know which) and thought it wasn't one of Lewis' better arguments. But I wonder whether I only saw the older version, & don't know how to tell. Any comments on the difference would be appreciated.

Chad said...

I’ve recently been quite intrigued by this argument myself and have been starved in trying to find a solid reference like this! Thanks!

Here’s what I think is a good syllogism similar to the argument Lewis proposed:

1. As determinism holds, all beliefs are the product of nonrational causes.

2. If a belief has only nonrational causes, then
a. it cannot be true;
b. it cannot be justified;
c. we have no adequate reason to think it likely to be true;
d. the person holding it has no adequate reason to think it likely to be true; or
e. it cannot be held because it is true.

3. Therefore, if determinism is true, then
a. it is not true;
b. we are not justified in believing it; or
c. we don’t believe it because it is true. (From 1 and 2)

4. If we don’t know that we don’t believe p because it is true, then we aren’t justified in believing p/don’t know that p.

5. Therefore, determinism is
a. false (from 3a); or
b. unjustified (from 3b or 3c+4).

As for premise (1), I define “nonrational causes” as causes influenced by random or mechanistic movements of insentient particles governed by the laws of physics.

What do you think?

Lastly, doing my own thinking on the matter, I’ve personally conceived of the following argument (unaware if a similar form exists) and would likewise be interested in having your thoughts regarding it, as you’ve hopefully gleaned some helpful insight from Reppert’s book:

1. Nonrational causes produce only nonrational effects.
2. Humans are the effect of either rational or nonrational causes.
3. Humans are rational.
4. Therefore, humans are not the effect of nonrational causes.

Weekend Fisher said...

I'll wait until I hear the blog author weigh in on this but I'd like to mention that the syllogisms you put forward are fairly easy to poke holes in. I'll see if there's a stronger one forthcoming before I go poking holes though.

Take care & God bless

Chad said...

You think so? What do you mean by "poke holes"? Do you mean to say they're unsuccessful, or merely 'able to be challenged'? If unsuccessful, do you mean in terms of logical composition or in the face of challenges? If the latter, do you think those challenges cannot sufficiently be met?

Anonymous said...

In the last decade or so, much attention has been focused on Alvin Plantinga's argument that the belief in naturalism is "self-defeating" and (hence) irrational. His main argument seems to bear significant resemblance to Lewis' insight. Here's one rough summary/formulation of the argument:

Say that N = naturalism; E = evolution; and R = our faculties are reliable (i.e. in the production of true beliefs). Plantinga asks how we are to assess the probability of R on the assumption that both N and E are true, that is, what is P(R/N&E) (what's the probability of R, "on" or given N and E?) Plantinga argues that it is either low or inscrutable; in either case, the person who accepts (N&E) has a "defeater" (something that undermines one's justification or warrant) for (holding the belief that) R, and therefore for any other belief one might hold (since that belief B will be the product of those faculties mentioned in R).

That's already a problem. But now suppose we examine the belief that (N&E) is true. Well, if one accepts (N&E), then, according to this argument, one has a defeater for (N&E). Hence, it is self-defeating, and irrational to believe in the truth of both naturalism and evolution.

Obviously, a lot more needs to be said to make the argument work (e.g. why must the probability of R on N&E be low or inscrutable?), but again the main insights resemble those mentioned by Lewis (e.g. there is no good reason to suppose that our faculties will produce TRUE beliefs, as opposed to beliefs that are ADAPTIVE or CONDUCIVE TO SURVIVAL; and there are reasons to think that beliefs of the latter kind need not be (even very often) true).

For a recent look at many of the details of this argument, including counter-arguments, see Beilby, James (ed.) (2002) Naturalism Defeated? (Essays on Plantinga's Evolutionary argument against Naturalism.) Cornell University Press. Plantinga has written a whole bunch on this general topic - it should be easy to find references for his work (e.g. around pg. 220 in his 1993 "Warrant and Proper Function", and a number of articles).

Anonymous said...

Great points Phil. Many times I’ve run into criticisms of Lewis’ arguments that seem to assume that his arguments have been completely refuted. Balderdash! His arguments are sound and have stood well over the years (I still find his arguments in Miracles to be compelling).

Weekend Fisher said...

Hi there

Don't get me wrong, I appreciate a lot of Lewis' arguments. I just think this is not one of his better ones.

Chad, when it comes to the way you laid out Lewis' arguments (or a version of them), I'd "poke holes" through the first one at 2a/2b, and on the second one at point 1, and both for the same reason. We've never defined "rational"; let's define it right quick. A full conversation would run long but let's start with simple "truth" being basis of rationality. On some definitions, "truth" means "corresponding to reality." Which means that, if the mind successfully tracks and models what is happening, it's rational; all that's necessary is successful mimicking, modeling, or correspondence between our minds and the world around us. Which means that so long as the mind reflects what is happening around it, then "non-rational" causes (causes which don't think) produce "rational" effects in the human mind (mirror what's going on around them).

If you're interested in going back and forth kind of seeing where the arguments go, we might want to have pity on the comments section here and go to our own blogs.

Take care & God bless

Chad said...

Yes, that's a good thought. My blog doesn't see much action if you want to travel over there unless you prefer it at yours.

Before we get into things, as I hope you're interested, can you tell me a bit more about yourself? Areas of particular study/specialty, basic beliefs, etc? It helps me to understand that I'm conversing with a human and not merely a machine.

Thank you for your reply!

Weekend Fisher said...

Hi Chad

Sure, I love that kind of thing. You can start off on your blog if you'd like, and then I'll either comment there or reply at my own blog and put a notice on yours.

Last time I had an on-line "exchange" like this ... just a note on saving time here ... some poor guy said he'd take the first post in the series and then spent like 3 paragraphs supporting his view that Paul wrote the Pauline epistles -- which I would have gladly handed him for free and saved him a bunch of research and typing. So the upshot is that I'm conversational, I'm not out to hammer you, for me it's the thrill of the hunt for truth.

Just as an intro, my degree is in psychology but when I got into the real world I hated it (didn't have the maturity to deal with that level of problems back then, I think). For the last ... oh, what, 15 years now I guess ... I've been making my living working as a programmer because that's just the kind of thinking that's native to me. I'm a rabid bookworm, favorite reads are history and theology. I'm an amateur linguist, currently trying to pick up Arabic. On the personal side, I'm a mom with 2 kids (Dad skipped out years and years ago). I like bike rides and cooking and am having a blast Christmas-shopping for the little people. As far as beliefs go, I've looked around and studied. Theologically I'm somewhere between conservative Lutheran and Eastern Orthodox; the church where I'm a member is Lutheran (WELS/UAC). Btw I have a passion for other religions in the sense of recognizing the "preparatorio" in them and not misrepresenting them. I have a decent comparative religion section in my bookshelves.

Take care & God bless

Chad said...

Excellent! I’m ecstatic to hear of someone with similar habbits/interestes as my own. Hopefully that’ll serve to expedite our ability to get down to matters of fact. Unfortunately, I may have to temporarily postpone this discussion for reasons of busyness: An atheist Prof. (Yonatan Isaac Fishman of AECOM) seems to have challenged the apologetic material on a friend’s site that I occasionally write for, so preparing for that encounter might be in store. If you would, pray that this goes well, as I will pray for you and your children.

Thank you for your splendid response; I look forward to our conversation. I’ll be sure to keep in touch, (it shouldn’t be long until I offer a response on my site).

Phil Steiger said...


Thanks for writing and for the insights. I apologize for taking a couple of days to respond…life and all.

First, you should know that Brian may sound like a smart guy, but he is.

Weekend Fisher-
You wrote, “Could you give any insights on the differences between the first version of Lewis' argument and the second?”

Let me give you the versions Reppert outlines in his book. Doubtless there is more to the difference than these two syllogisms, but they probably give a good basic outline.

First syllogism:
1. No thought is valid if it can be fully explained as the result of irrational causes.
2. If materialism is true, then all thoughts can be fully explained as the result of irrational causes.
3. Therefore, if materialism is true, then no thought is valid.
4. If no thought is valid, then the thought, “materialism is true” is not valid.
5. Therefore, if materialism is true, then the thought, “materialism is true” is not valid.
6. A thesis whose truth entails the invalidity of the thought that it is true ought to be rejected, and its denial ought to be accepted.
7. Therefore, materialism ought to be rejected, and its denial ought to be accepted.

Second, updated syllogism:
1. No belief is rationally inferred if it can be fully explained in terms of nonrational causes.
2. If materialism is true, then all beliefs can be fully explained in terms of nonrational causes.
3. Therefore, if materialism is true, then no belief is rationally inferred.
4. If any thesis entails the conclusion that no belief is rationally inferred, then it should be rejected, and its denial accepted.
5. Therefore materialism should be rejected and its denial accepted.

Apparently Anscombe rejected the first argument in part because she believed Lewis conflated irrational causes with nonrational causes, her belief being that naturalism is not committed to the stance that beliefs are caused by irrational causes, but by nonrational causes. A second critique of hers concerned the separate point of materialism being able to support paradigm cases of rational and irrational inference, thus giving materialism a way to gauge rational inference without appealing to non-material things.

Anyway, I hope that is at least a little bit of help down the path.

Phil Steiger said...


Your argument about determinism and the truth of or justification of is, I think, playing on the same idea as Lewis’s. Are you possibly throwing in a kind of Kantian assumption in the first premise (not necessarily unjustifiably) when you take physical laws to be deterministic? And thus there needs to be something else in the human experience to justify knowledge or rational inference (phenomena vs. noumena).

And then your second syllogism makes perfect sense to me. Of course, one major move at premise 1 might come from a theory of emergence-that consciousness is an emergent property on brain activity. But I am in no shape to guess at such an attack on the premise as I have little to no real grasp of the different views regarding emergence.

Anonymous said...

Chad - an analogy that might be helpful in seeing Weekend Fisher's (and Phil's) point regarding premise 1 of your 2nd syllogism ("Nonrational causes produce only nonrational effects"):

(1): Non-biological causes produce only non-biological effects
(2): Non-living causes produce only non-living effects
(3): Non-economic causes produce only non-economic effects
(4): Non-highly-ordered causes produce only non-highly-ordered effects.

Each of these has more or less obvious counterexamples (having a 2000-pound stone dropped on a living organism; the sub-cellular chemical processes that subserve organic life; Hurricane Katrina; and Hurricane Katrina (or any example from Complexity Theory), respectively - many more would be easy to come by).

And as Weekend Fisher points out, the problem with each is a vague or equivocating or false definition of each of the major terms (so, in this case, "non-rational" and "rational"). We can certainly stipulate definitions that would make the sentences turn out true, but they might be "trivially" true, in the sense that they don't capture what we really mean to talk about; or they might be question-begging against the materialist, in the sense that we incorporate anti-materialist assumptions, of the kind that are at the center of dispute, directly into the definition.

Doesn't mean it can't be done - but perhaps the analogous examples help show where precisely the difficulty lies.

And Phil - even though all of your thoughts and comments bear the marks of great intelligence, it nevertheless and despite that fact remains the case that you have such intelligence. Sorry, but it has to be said.

Weekend Fisher said...

Thanks for the clarification.

But on the second one I'd still object to the opening premise and on basically the same grounds ...

Take care & God bless

Steven Carr said...

Rational inference cannot be explained supernaturally.

Therefore the supernatural does not exist.

Victor cannot produce a supernatural explanation of why it is logically impossible, given the rules of chess to deliver checkmate with King and Bishop against King.

Victor Reppert said...

This is a good resource page for material on both sides of the AFR controversy.