Baloo

bd_from_kg,

I guess the piece of the puzzle that I don't quite see in any of this is the argument that the validity of a thought hinges on the manner in which that thought was brought about. If a thought or belief can be articulated in terms of true premises leading to logical conclusions, but only popped into my mind when I slipped and smashed my head on the ground - would you be rationally justified in rejecting it? Would you even be rationally justified in factoring "how I got the thought" into your analysis of the validity of the thought?

bd-from-kg

Baloo:

It doesn’t, at least in the sense in which you appear to be using the term “validity”. A valid proof is valid regardless of how it was produced. But that’s not how Lewis is using the term “valid”. What he seems to mean by “no thought is valid...” is closer to “no belief is rationally justified...”.

First, let’s ignore the “true premises leading to logical conclusions” part and suppose that only the conclusion popped into your mind. Also, suppose that I have no independent way of “testing” your conclusion against other evidence; that my only evidence that it’s true is that you believe it. Then obviously the answer is that yes, I would be rationally justified in rejecting it, and so would you.

Now let’s take this one step further. Suppose that the entire argument, including premises and conclusions, popped into your mind, but that the argument was so complicated (like Cohen’s proof of the independence of the continuum hypothesis) that neither of us was in any position to determine that it was a valid proof. Then again (assuming as before that I have no other evidence to go on) I’d be rationally justified in rejecting the conclusion (and so would you).

Finally, to get as close as possible to Lewis’s point, suppose that the entire apparatus needed to evaluate such a proof, including your beliefs about what does and does not constitute a valid (i.e., justified) inference, popped into your mind at the same time as the proof itself. What rational justification would you have for assuming that these beliefs about what constitutes a valid inference are true? Obviously, none at all. In other words, if your cognitive faculties had simply “popped up out of nowhere” and you realized this, you would have no rational justification for trusting them to be reliable. You’d be in essentially the same situation as if you had been presented with Cohen’s proof but were in no position to evaluate the validity of the reasoning, except that in this case the reason you’re not able to evaluate the validity of the reasoning is that the very faculties that you’d have to use to do the evaluation are the ones that need to be evaluated.

Note that the claim is not that it’s impossible that your cognitive faculties might be reliable under these conditions; but that you have no rational justification for believing that they are, given that you have no idea where they came from; they’re of unknown provenance; they arrived with no credentials, so to speak.

Silent Acorns

Lewis' critique of Naturalistic Rational Atheism (NRA), as Clutch said, is based on the idea that we cannot be sure that our thought processes are rational if they are the direct result of non rational processes. While Lewis admits that an evolutionary mechanism could produce reason, he argues that we can never know that such a mechanism actually exists because we need to use our questionable "reason" to prove it. Therefore, Lewis concludes, NRA can never prove itself to be true. Then, Lewis claims that theism has a way out of this quagmire, by calling on a god who supplies reason from outside natural existence.

To Lewis, this counts as a point in favor of Theism over Atheism (I'm not sure if he considers this to be a winning point though ... ).

To me though, his argument is nothing more than saying: "NRA is based on an axiom that our minds are capable of rational thought", and then trying to claim that this is somehow a flaw. The hypocrisy of Lewis' argument to me is that he would never argue that this axiom is false (in fact his whole argument implicitly assumes it to be true). All he is saying is that under NRA this axiom is a necessary assumption, while in Lewis' Theology it is the direct result of his external god.

Or is Lewis only saying, "Don't criticize us for believing in an unprovable god when you believe in an unprovable reason"?

Llyricist

No, I meant what I said originally, that is, reasoning came about from observing, and understanding cause and effect relationships in nature, i.e. based on, I never said that was all reasoning was, in fact I said we have built on it and expanded on it, and turned it into an abstraction, to the point where obviously some great thinkers have forgotten the basis.

And the point was that reasoning itself can not be seen to have been caused by non-rational means in nature, since rationality usually means "based on reason", and if reason is based on understanding cause and effect, and nature generally exhibits cause and effect (quantum fluctuations aside). Then it's irrelevant whether nature is rational or not, since both nature and reason are generally causal.

And the point of my post regarding your re formulation of Lewis' words, was that if you only include thoughts arrived at rationally in the set of all human thought, then they all MUST have been arrived at rationally. But this not what was intended in the argument, what was intended was human reason itself, NOT all instances of human reasoning, these are two different things.

As for your formulation that all reasoning may be the product of bad cognition, this I accept and have no quarrel with at all, except that I have no use for it until some character wakes me up out of my pod.

Baloo:
Exactly

bd-from-kg

Clutch:

So far so good, as long as we understand “inference” to mean essentially the same thing as “reasoning” in the broad sense. And it does seem that Lewis is not distinguishing clearly between the two.

By the way, I gather (from reading the entire chapter in question) that Lewis considered (1) to be equally valid whether one interpreted “based” in the “historical” or “constitutional” sense, but it seems to me to be plausible only if one reads “based” as meaning “historically based”. It seems clear to me that physical processes can support rational processes; at any rate I can discover in myself no trace of any intuition to the contrary. I really don’t see how a theist could seriously doubt that, if God decided to design physical processes that support rational cognitive function, He could do so. I think the real concern here (for a theist) would have to do with libertarian free will, which is a completely different issue.

Indeed. After all, even the most devout theist must admit that there are people (not to mention other beings) whose cognitive faculties are clearly not reliable even though (on common theistic assumptions) they were created by God. What’s more, we have no way of knowing whether God (of there is one) would have wanted to give us reliable cognitive faculties, especially since one pretty much has to adopt an “unknown purposes” viewpoint to make theism even remotely plausible. So the theistic “way out” of this difficulty just doesn’t work. The sad fact is that if our cognitive faculties are reliable we have absolutely no way, in principle, of knowing or verifying that they are.

But if they’re not reliable it’s possible that we could know that they aren’t, because they might produce clearly inconsistent conclusions (shades of Godel), or to the conclusion that they’re not reliable. In the latter case we can’t have “good reasons” (rational justification, if you will) for thinking them reliable. For if they aren’t we have no rational justification for believing anything at all, but if they are, we have a strong “defeater” for the belief that they are, so again we aren’t justified in believing that they are.

So it seems that the best that we can say is that a necessary condition for being rationally justified in believing that our cognitive faculties are reliable is that they produce consistent beliefs and (more importantly for present purposes) that they not lead us to the conclusion that they’re not reliable. Moreover, any theory or metaphysical system that leads us to this conclusion must be rejected for the same reason: accepting it would force us to the conclusion that none of our beliefs is rationally justified.

Certainly that’s the real point at issue. But I’m not clear about why you say that it’s unwarranted. What counts as “warrant” for a fundamental intuition of this sort? Is belief in the Principle of Induction warranted? If so, how? What about Ockham’s Razor? What about the principle that you shouldn’t believe any (nontautological) proposition without at least some evidence? What’s the evidence for that? What’s your justification for thinking (if you do) that one needs evidence for it?

No. As I’ve pointed out before, Lewis concedes that rational processes could arise from nonrational processes. What he’s arguing is that you’re not justified in believing both that your own cognitive processes are rational and that they can be traced entirely to nonrational processes. In other words, for Lewis, (1) is not based on some still deeper principle, but is itself a deep fundamental intuition that we all share.

OK, I’ll do my best. But by way of preparation it may be helpful to look at a famous passage from Richard Thomas’s Metaphysics:

Now it’s important to note that, even if the stones came to be where they are by a natural process, they can certainly be evidence. They could be evidence, for example, of an avalanche. But they cannot be evidence that you’re entering Wales unless someone deliberately arranged them into a pattern forming the “Welcome to Wales” message. The point is that in the latter case the stones are being taken to represent some fact beyond the brute fact of their being there. Your conclusion that you are entering Wales is based on the assumption that the stones were arranged with the intent and purpose of conveying that information. If they weren’t – if the pattern is the result of blind natural processes – there is no rational justification for believing that the message they represent has any connection with reality.

We can take this a step further:

(*) If the process itself that created a structure or pattern is the result of blind natural processes, there is no rational justification for believing that the structure or pattern represents or betokens any fact beyond itself. If it appears to do so, there is no justification for supposing that the purported “fact” that it appears to represent is true.

We can think of this as a sort of “improved version” of Lewis’s “Rule”:

So much for preliminaries. Now here’s the best (modified) version of Lewis’s argument so far as I can see.

(1) As I pointed out earlier, we can’t know that our own cognitive faculties are reliable, and no reasonable metaphysical system can remedy this (without also yielding clearly counterfactual conclusions, such as that everyone’s cognitive faculties are reliable). So it’s unreasonable to ask a metaphysical system to provide us with any assurance that they are, or to criticize a metaphysical system for failing to do so.

(2) But we can insist that a metaphysical system not lead to contradictory beliefs, and that it not lead to the conclusion that we are not rationally justified in believing that our cognitive faculties are reliable. Any metaphysical system that does so is out of court.

(3) Any reasonable metaphysical system must include a number of “presuppositions”: axioms that are not supported by any evidence. Examples are the Principle of Induction, Ockham’s Razor, and the axiom that one is not rationally justified in believing any non-tautological proposition without empirical evidence. (Many people would add the axiom that arguments that rigorously adhere to the “laws of logic” are truth-preserving.) But there are others as well, such as the assumption that more knowledge is better than less, or that true beliefs are better than false ones. These axioms are supported by deep fundamental intuitions which we have no choice but to accept as true, because they are the foundation of all of our other knowledge. We might call these foundational axioms.

(4) One of these fundamental intuitions is (*) above: If a structure or pattern that appears to represent some purported fact was produced by a process that is itself the result of blind natural forces, there is no rational justification for believing that it represents any fact beyond itself.

(5) But metaphysical naturalism entails that our cognitive faculties are themselves ultimately the result of blind natural forces. And of course, our beliefs are precisely “structures of patterns that appear to represent some purported facts beyond themselves – namely, the facts that the beliefs are beliefs about.

(6) So MN leads to the conclusion that none of our beliefs is rationally justified.

(7) But the whole significance of the notion of rational justification is that we have another deep intuition that rationally justified beliefs have a far better chance of being true than unjustified ones; in fact that beliefs that are not rationally justified will be true only if we happen to get lucky.

(8) So MN leads us to the conclusion that our cognitive faculties are not reliable.

(9) Therefore MN is out of court.

As a postscript, (a la Lewis), we can point out that the argument that in this case the theory evolution gives us an explanation of how these particular processes (our cognitive faculties) could reliably produce representations of actual facts is also out of court, because the belief in evolution is itself one of the very patterns or structures in question, and therefore cannot legitimately be taken as “testimony on its own behalf”.

Clutch

bd,Well, you're running two things together here, too. One is why I find (1) unwarranted. The answer is, Because I can't see where anyone gives any reason to believe it's true. The other is, why should its being unwarranted count against it, since there are some famous examples of indispensable principles that we find difficult to recover evidentially. (Ockham's Razor is not one such, in my view, but whatever.)

This second line of thought is hard to understand. What makes those special cases special is indeed their indispensability. Surely you don't believe the lesson of the Problem of Induction to be that, in general, lack of warrant is neither here nor there with respect to the plausibility of some principle! But then, I can't see what else you're suggesting here.

Taken historically, (1) smacks of a priori science, and ad ignorantium. I can see why someone would believe it, just as I can see why someone would believe that a large animal just couldn't be made up of tiny little organisms. But I can't see why the former should be taken seriously by anyone who recognizes the defects of the latter. Nor do I see why calling (1) a "deep intuition" that we are supposed to share is any more effective than positing a similar deep intuition would be in the latter case.This is wrong twice over. First, I don't share this intuition; and I see no indispensability or consequential argument looming to show that this is a cognitive defect on my part. (Compare, eg, a failure to share the intuition that the future will resemble the past...). (*) is neither warranted, nor indispensable, nor intuitive to me; and hence your (4) is just false, so far as I can see. Shall I conjure up a deep intuition that mental illness is fundamentally demonic, and then offer arguments that only seem vaguely plausible to people who already share this intuition?

Second, the repeated allusions to "blind natural processes" throughout your reconstruction of the argument shows that Lewis, or you-on-his-behalf, is not engaging any real interlocutor. The relevant historical mechanisms taken to explain the existence of rationality are not "blind" in the way that seems to be intended -- ie, accidental. The survival value of correctly representing elements of one's environment is not seriously open to question; and the step from the value of truth to the value of truth-preservation is no step at all.

Thanks for your careful and well-written post. It helped clarify the issues.

bd-from-kg

Clutch:

As it happens, it’s more convenient for my exposition to take your points more or less in reverse order.

On the contrary, the term “blind” is perfectly apt. It refers to the fact that the processes involved are undirected; purposeless; not “aimed” at any end or result. There’s nothing teleological about the “forces of nature” (at least according to MN). While many of those who defend this argument do use words like “chance” and “accident”, I prefer not to since I’m not sure that they’re appropriate. But the term “blind” captures the meaning perfectly.

First off, on reflection I think (*) is a little too complicated to be a “fundamental intuition”. The intuition (i.e., the thing that seems “self-evidently” true) is something like:

(**) It is irrational to believe both that a structure or pattern is the result of blind natural processes and that it is evidence for some purported fact beyond itself that it seems to represent. Or in other words, there is no rational justification for believing that that the product of undirected, purposeless natural processes signifies anything beyond itself – i.e., what its mere existence at that time and place implies.

The statement I labeled (*) is a pretty obvious corollary of this.

Now if you say that you don’t share this intuition (or something very like it) all that I can say is that I don’t believe it. As Thomas says of his “Welcome to Wales” example:

You understand this perfectly well, and you didn’t have to think or reason about it in order to know it. A three-year-old would know that if this pile of stones was indeed produced by an undirected, purposeless natural process like an avalanche or earthquake, the fact that it happens to spell out “Welcome to Wales” signifies nothing.

Thomas gives another illustration of this point. Suppose that you dig up a stone with interesting marks on it. It turns out that they can be interpreted as a message in an ancient script saying, “Here Kimon fell leading a band of Athenians against the forces of Xerxes." If you believe that these marks were the result of volcanic activity, you cannot also believe them to be evidence that Kimon actually fell here. Everyone who isn’t a complete idiot recognizes this.

Here’s a more modern example: Suppose a computer prints out the message, “FIRE!” If you think that the message is coming from a message that someone just sent, or that the computer is hooked up to some sensing devices and has software for processing it, you might reasonably believe that you’re really in danger. (The reason this is reasonable is that the message was produced by a conscious mind – in the first case directly, in the second indirectly. And a conscious mind does have direction and purpose; its actions are “aimed” at some end.) But if you believe that it’s the result of a software glitch, you can’t also reasonably believe that it signifies anything.

Here’s a simple example. Suppose that an arrow formed from sticks is commonly used to indicate “this way to shelter”. Now suppose that a three-year old boy who knows this wants to find shelter. He notices that the wind groups a few sticks into the form of an arrow. Do you think that he’ll conclude that there’s shelter in the direction indicated by this arrow? Of course not! Even a three-year old recognizes the principle. How can you seriously claim that you don’t?

In fact, it’s a very safe bet that every moderately reflective person prior to, say, 1750, would have said unhesitatingly not only that he had such an intuition but that it was so strong and compelling that he was quite certain that it was valid in all cases. Can you seriously contend that all of these people were wrong, not only about whether it could possibly be wrong in even a single case, but about whether they even had such an intuition?

[Note: Lewis’s examples are all instances of this principle. In fact (as I’ve learned since posting the excerpt from Miracles), Lewis later published a revised version of his argument which made it clear that his intention was to distinguish between beliefs that are caused essentially by blind natural processes (a liver attack, a bone pressing on the brain, etc.) and those with a “ground/consequent” cause – i.e., which are the product of reasoning – and not to distinguish between beliefs produced by faulty reasoning and ones produced by valid reasoning.]

Obviously everyone who is capable of rational thought at all recognizes the principle involved in these examples and has a fundamental intuition that it is valid. To argue otherwise is essentially to put oneself in the position John Galt Jr. did in the Special Creation v Evolution thread when he said:

(Actually the entire thread is an extended riff on this theme.)

Of course one can deny that he recognizes Ockham’s Razor as a fundamental intuition about rational justification, and there’s no way to logically disprove such a claim, but it just makes one look silly. And this doesn’t just apply to fundamental intuitions about things that are clearly essential presuppositions of rational thought. For example, anyone who denied that he has a fundamental intuition that space is Euclidean would look equally silly even though it now appears that space is not Euclidean.

Huh? But large animals are not made up of tiny little organisms! More to the point, no one has ever, to my knowledge, claimed to have a “fundamental intuition” that animals cannot be composed of lots of very small units. And no one, to my knowledge, was particularly surprised when the units in question (cells) were discovered.

It seems to me that a better example would be a person who believed that something cannot be both a particle and a wave, or that nothing can be in two places at the same time. It is perfectly rational to believe such things very strongly, even in the absence of any evidence to the contrary, because we really do have very strong fundamental intuitions that they’re so. What would not be completely rational would be holding on to such beliefs in the face of very strong evidence that they’re false. But I’ll argue below there cannot in principle be evidence that (**) is false.

You don’t see why an actual fundamental intuition should be taken seriously because we don’t also take a wholly imaginary, nonexistent intuition seriously?

First off, let’s not use the term “warranted” here, because this has come to have a somewhat different meaning from “rationally justified” (RJ) in the theory of knowledge. Let’s just talk about whether a belief is RJ.

In this terminology you’re implying that no belief is RJ unless one can “give a reason” for believing it. And of course this must be an epistemic reason; reasons like Pascal’s Wager or “It makes me feel good” or “It works for me” are out of court in this context. But this is untenable for reasons that are pretty well known. In fact you abandon it in your very next statement:

But this would seem to be a pragmatic reason, not an epistemic one, for accepting such principles. Doesn’t “indispensability” just amount to “It works for me”? What epistemic reason can you give for believing that “indispensable” beliefs are necessarily true?

Besides, it seems clear that not all such beliefs are “indispensable” in any intelligible sense. For example, take the belief that knowledge is better than ignorance. (I’ve often expressed this principle this way: if you know [or have strong reason to believe] that you would choose to do X if you had enough knowledge and understanding, you should do X.) Isn’t this a basic presupposition of rationality? But how is it indispensable? Or the one that I cited earlier: that one should not believe anything nontautological without evidence? In fact, this can be strengthened to “without sufficient evidence”. Don’t we have a fundamental intuition that this is true?

To get closer to the case at hand, don’t we have a number of basic intuitions about what constitutes evidence and how much and what kind of evidence is “sufficient”? But how are these presuppositions indispensable? More to the point, how can we possibly know a priori that they’re indispensable, or for that matter that they’re correct? And if we try to justify them on the basis of evidence we have a problem of circularity: these are the “ground rules” for evaluating evidence. How do we evaluate any purported evidence for them as to its relevance or sufficiency without applying the very ground rules that we’re trying to justify?

The rules that I described are rules about when a belief is rationally justified. Such rules are necessarily a priori. Before we can do any reasoning at all we have to have a pretty clear notion of what constitutes reasoning; what constitutes evidence; in short, what the ground rules are; when a conclusion is rationally justified. Otherwise we would be in the same position as someone trying to play chess without knowing how the pieces are allowed to move or when the game is over.

But such rules do not constitute “a priori science” because they aren’t scientific beliefs at all. They are beliefs about what constitutes science. Science is powerless to tell us what the “scientific method” ought to be: how we should evaluate evidence, etc. This sort of thing is logically prior to science itself. And since such beliefs cannot, by their nature, be based on evidence, they can’t be refuted by evidence.

To summarize the argument:

(1) We do indeed have a fundamental intuition that (**) is valid.

(2) Unlike some other fundamental intuitions (like the intuition that space is Euclidean), this one cannot be falsified by evidence because it's about what constitutes evidence; what constitutes rational justification. In other words, it’s part of our “ground rules” for evaluating evidence; for what constitutes valid reasoning. Thus any attempt to reason from any evidence to the conclusion that (**) is not valid is automatically out of court. One cannot claim to have rational justification for repudiating one of our fundamental insights as to what constitutes rational justification. One cannot prove evidentially that our rules for evaluating evidence are invalid.

The rest of the argument, of course, is the same as before: MN, combined with (*) (which is entailed by (**)) implies that we have no rational justification for any of our beliefs, which puts it out of court since this implies that we have no rational justification for believing MN itself.

luvluv

Good stuff, Clutch and bd-from-kg.

Has anyone mentioned that Lewis' grounds for disputing the ability of reason to perceive the outside world ahappen to be the grounds upon which many atheists on this very website deny the validity of relgious experiences?

If you say that your ability to form inferences can be caused both by physical causes within your brain and the external world, then how can you say that religious experiences cannot both be caused by physical causes within your brain and the external world?

If you accept this about inferences, wouldn't you have to accept this about religious experiences?

Clutch

bd, thanks again for your remarks. They seem to make the same mistakes, though.

I said:And you replied:I'm glad you disown the implications of "accidental". But it's unclear that your own characterization of "blind" passes the no-straw-man test.

If "blind process", in your lexicon, is consistent with "process in which accurate-belief formation capacities and justification-preserving inferential capacities can develop incrementally and be selected for", then call the processes blind all day long. But then, Lewis' argument falls apart; blind processes can result in systems with reliable truth-preservation capacities, and it can be reasonable to think that's happened.

If "blind process", in your lexicon, is not consistent with [...long description...] then it's a straw man. The relevant processes are not blind in that way, and this matters in making sense of the analogy you repeated.Well, I thought we'd given up "accidentally".

Anyhow, if I knew that the arrangement of stones was literally accidental, I wouldn't trust it.

If I knew that the arrangement of stones was the result of "ordinary interactions of natural or physical forces", meaning "typical daily observed processes", I wouldn't trust it.

If I knew that the arrangement of stones was the result of "ordinary interactions of natural or physical forces" as they occurred in some widespread and massively evidenced sort of process that plausibly would lead to the proliferation of accurate welcome signs and the extinguishing of inaccurate welcome signs... I would (if a range of other conditions were met) trust it.

All the example shows is the possibility of producing bad analogues of evolutionary theory that equivocate on crucial terms, and fail to bite when the equivocation is removed. But since I never proposed any limits on the ability of Lewis or Thomas to construct unfecund analogies, this does not impugn any claim of mine.

Now, you had claimed it was a "deep intuition" that: I canvassed my stock of intuitions, though, and explained (i) that I don't share this intuition qua intuition, (ii) that there is no rational warrant on display for it, and (iii) there are no pragmatic or consequential reasons to think that declining to accept it as a general principle in spite of (i) and (ii) will be self-defeating, unfeasible, absurd, or any other sort of defect that would accrue to denying (eg) the reliability of induction.

You reply, Well, the falsity is a problem too, but as long as we're on the same page I'm happy. Here's the thing. As a universal generalization, I think (**) is false. I think it's false because I have pretty good warrant for taking (E) to be true:

(E) Human belief-forming capacities and human reasoning capacities evolved via natural processes undirected by any rational agency.

Now, either (E) is either a counterexample to (**), if "undirected...yadda yadda" is meant to describe evolutionary processes, or (**) has no bearing on any view that anyone actually holds. False, or irrelevant; in either case, (**) is not a problem for naturalism.

Of course, as I've explained already, I'm happy to assert the following:

(A) Not every product of non-rational historical processes is rational.

Heck, I'd even go the extra mile for this:

(B) Most products of non-rational historical processes are themselves non-rational.

And I expect the following is true, too, as a matter of elementary language pragmatics:

(C) In the normal run of events, the point of saying that a belief has non-rational causal antecedents is to communicate that it lacks rational causal antecedents.

Hence I cheerfully accept all the examples that Lewis can provide to shore up these three claims. What I don't see is reason to magic (A), (B) and (C) into a universal rule (**), still less a "self-evident truth". This would be bad reasoning in any case, even were there not independent grounds for thinking (**) false.

Finally, the weakness of the Lewisian argument is manifest in the very strange things you are then driven to say about it. Like:Huh?

If not for the recent arrival of Magus, this would be the oddest thing I've read here for a while.

I don't share the "intuition" (**) -- again, I think it is false. Your attempt to locate it in the realm of the "necessarily a priori" cuts no ice, nor does your simply asserting:False. I don't. (Is "we" just "everyone who thinks (**) is valid?)

(**) has exceptions: Humans are exactly such exceptions.

bd-from-kg

Clutch:

You seem to be under the impression that the basic argument hinges on the notion that the following implication is valid:

(+) If (**) is a fundamental intuition, then (**) is true.

But the argument does not depend on (+) or anything like it. In fact, I’ve cited several things that I think are obviously fundamental intuitions, but which appear to be false, such as “The geometry of space is Euclidean”, “Matter and energy are fundamentally different things, not different manifestations of the same thing”, and “Something cannot be in two places at the same time”.

The key premises in the actual argument are:

[1] (**) is a fundamental intuition.
[2] Some fundamental intuitions are of such a nature that they are indefeasible – i.e., they cannot be defeated by empirical evidence.
[3] If (**) is a fundamental intuition, by its very nature it must be indefeasible.

Or again, perhaps you’re under the impression that the argument requires that the following be true:

(++) If (**) is an indefeasible fundamental intuition, then (**) is true.

But that’s not right either. In fact, the argument doesn’t actually purport to show that (**) is true at all. What it purports to show is that any metaphysical system that leads to the conclusion that our cognitive faculties can be traced entirely to blind processes is “self-defeating” – that it is a “defeater” for the belief that our own cognitive faculties are reliable, and therefore for the belief that we are rationally justified in believing the conclusion. Note that this doesn’t mean that such a conclusion must be false, only that we can never be rationally justified in believing it.

[Note: To answer your question, of course the term "blind", as I’m using it, is consistent with your “long description” of an undirected evolutionary process. That’s the point of Lewis’s argument. But whether it’s “reasonable to think that’s happened” is what the argument is about. Is your idea of refuting an argument to simply assert that the conclusion is false?]

The reason that I say that you must be under some such misimpression is that you repeatedly bring up the claim that you have good reason to believe (E) as if this were a rebuttal or even a refutation of the argument, when in fact (let’s say it again) this is what the argument is about. What the argument claims to prove is precisely that any evidential argument that purports to show that our cognitive faculties are the product of blind, undirected processes is out of court because it is self-defeating.

Now as far as [1], [2], and [3] are concerned, as far as I can see you haven’t even attempted to argue against [2] or [3]; your whole focus has been on [1]. [I think this is a mistake, by the way.] And frankly, you haven’t really made much of an argument against [1]. For example, you claim that I have “simply asserted” that “We do indeed have a fundamental intuition that (**) is valid.” But this is a gross misrepresentation. I did not simply assert this; I offered several reasons for believing that it’s true. You’re the one who is simply asserting that you do not have this intuition:

I’ve explained at some length why I find this completely implausible. One of the strongest reasons is this: I find it very hard to imagine that you would say this if you had never heard of evolution. For example, suppose that you were someone like Thomas Jefferson: an intelligent, well-read person living in the late eighteenth century. Would you have any doubt whatsoever that you have a deep intuition that (**) is true? Well, if not, it follows that youdo have a deep intuition that it’s true. Knowing of evidence that it’s false doesn’t eradicate the intuition; it only overrides it.

Thus I can only think that what you really mean is that although you have this intuition, you also feel that you have good reasons to believe that it’s false in one particular case (namely evolution). That’s like saying that you don’t have a deep intuition that the geometry of space is Euclidean because, having studied general relativity, you no longer believe that it’s Euclidean.

Evidential arguments can show (in some cases) that deep intuitions are false, but they cannot show that the intuitions in question don’t exist. So if you’re arguing that you don’t have a deep intuition that (**) is true because for evidential reasons you have concluded that it’s false, you’re talking nonsense.

Another problem is that your claim that you “canvassed your stock of intuitions” is absurd. No one can “canvass his stock of intuitions”. For one thing, we have a number of intuitions that we’re not even aware of. For example, everyone has applied Ockham’s Razor routinely since the beginning of time, but if asked to “list” their deep intuitions no one would have thought to list this one until relatively recently. And even animals apply the Principle of Induction all the time, yet they are certainly not aware that this is one of their fundamental intuitions.

No, the way that we discover that we have a fundamental intuition is by analyzing our own thought processes and figuring out what the “unstated premises” are. These unstated premises are our real fundamental intuitions, whether we’re aware of them or not.

The intuition that the geometry of space is Euclidian is a good example. In Euclid’s day no one even thought to say that he believed that space is “Euclidean”. Rather, they simply took it as self-evident that, for example, the sum of the angles of a triangle is 180° . It was only much later that it was realized that this “self-evident truth” actually presupposed a certain kind of geometry, and that others were possible.

This is why examples are essential to determining whether we have an alleged fundamental intuition. We can ask “Why do I automatically conclude such-and-such in this situation? What am I presupposing must be true? What are the hidden premises here?” If what you’re presupposing is that the geometry of space is Euclidean, we may fairly conclude that this is a fundamental intuition. If what you’re presupposing is (**), we may fairly conclude that (**) is a fundamental intuition.

Thus I proposed a number of examples in which it seems clear that all of us would reason in a way that seems to presuppose (**). You more or less brushed them off with the statement:

But of course the examples were not intended to be “analogues of evolutionary theory”. And unfortunately you failed to explain what equivocation you were referring to. So at this point I have no idea what your argument is supposed to be here.

Later you suggested that all that these examples really show is that we believe some combination of:

• (A) Not every product of non-rational historical processes is rational.
  (B) Most products of non-rational historical processes are themselves non-rational.
  (C) In the normal run of events, the point of saying that a belief has non-rational causal antecedents is to communicate that it lacks rational causal antecedents.

But none of these, or all three together, can possibly be the intuition or “hidden premise” in the reasoning used in the examples. The fact that we believe that some or most non-rational processes do not produce “rational” results can hardly justify our certainty that the “Welcome to Wales” sign is not evidence that one is entering Wales if it was produced by a blind, undirected natural process like an earthquake. We feel certain that such things are never evidence, not merely that they usually aren’t evidence.

As for (C), there are always going to be “blind, undirected” forces at work, so obviously for the rule to make any sense at all it must be understood to apply only when the structure or pattern in question can be traced entirely to such causes. That’s why I’ve used phrases like “traced entirely to” many times in my exposition.

So clearly the fundamental intuition – the “hidden premise” - on which our reasoning is based in the examples is something far stronger than (A), (B), and (C). If it isn’t (**), what is it?

A couple of final points:

Lewis’s argument is against MN. MN entails immediately, without any evidence whatsoever, that human belief-forming capacities were produced by blind natural processes, because it presupposes that everything that exists was produced by blind natural processes. So before we can even start considering the evidence for evolution we have a crisis: our own cognitive faculties are presupposed to be produced by blind processes, but we have a deep intuition that there is no rational justification for trusting beliefs that can be traced entirely to blind processes. The problem, then, is how all this evidence for evolution is to be made “admissible”; how do we justify accepting the outputs of these presumptively untrustworthy cognitive processes which say that those cognitive processes are trustworthy after all?

Finally, there’s a serious question of whether we have good reason to believe (E). Clearly we have very good evidence (if we can get around the problem I just described) that human belief-forming capacities and human reasoning capacities evolved via natural processes. But what evidence do we have that these processes were “undirected”? It won’t do to simply presume that they were, because then you’d be arguing in a circle: “(**) isn’t true as it applies to human cognitive faculties because I presume that the process that produced them was undirected – i.e., that (**) isn’t true as it applies to human cognitive faculties.”

Certainly the hypothesis that the process of evolution was directed is completely out of court in a scientific theory. But the function of science is to come up with the simplest possible naturalistic explanations for observed phenomena; it makes no claim that these explanations are true, much less that they’re the whole truth. In fact, since the methodology of science excludes any hypotheses incompatible with MN a priori it’s disingenuous to argue that the fact that they don’t appear in the best scientific hypothesis shows that they must be false. The fact that they wouldn’t appear was built in to the methodology at the outset; it was a given.

Just the same, it’s plausible to argue that this hypothesis should be ignored in the absence of any direct evidence for it if the alternative – the hypothesis that the process was undirected – does not lead to the conclusion that human cognitive faculties are unreliable. So we see again that you’re putting the cart before the horse. You have to show that the hypothesis does not lead to this conclusion – or in other words, that you are justified in rejecting (**), at least as it applies to evolution - before you can assert that you have good reason to believe (E). So you cannot argue that you are justified in rejecting (**) because you have good reason to believe (E).