Vorkosigan

But haven't you subtly changed the argument here? The question is, "Where does reason come from? Can it derive from irrational processes?" If it derives from irrational processes, how can we know this? Only by the application of our reason. But then we have to assume that our reasoning is valid in the first place. But how can we assume our reasoning is valid if it derives from an irrational process?

What is meant by "irrational?"

Michael

bd-from-kg

boneyard bill:
I don't think so. If I have, you certainly haven't indicated how.

The naturalist's answers are "It developed through evolutionary processes" and "Yes".

The question seems to be based on Lewis's "Rule" that no thought is valid if it can be fully explained as the result of irrational causes. Aren't we going around in circles? Unless you can offer a sound, non-question-begging argument for believing that this rule is valid and applies to the process of evolution, the fact that, according to evolutionary theory, our "reason" derives from "irrational" processes must be considered irrelevant to the question of whether it is generally reliable.

Absolutely right. Any reasoning whatever inherently presupposes that our reasoning is valid. As for whether or why we are justified in making this presupposition, or the related presuppositions that it is possible to make sense of the world (by applying the Principle of Induction and Occam's Razor, among other things), as I noted earlier, this is a separate question. The question that Plantinga (and scilvr, I gather) are addressing is whether naturalism is self-defeating - i.e., whether it provides rational justification for rejecting it. The question you're addressing is that of the radical skeptic: do we have grounds for believing anything at all?

As Fitelson and Sober point out in the conclusion of the article cited by Bill Snedden above:

[ January 22, 2002: Message edited by: bd-from-kg ]</p>

faded_Glory

Well, I am a naturalist, but I am inclined to agree with scilvr that we should be very suspicious of the reliability of our reason to lead us to real insight (I try to avoid the word 'truth').

I am also a natural scientist, and the adagium of the field is that we have to take it very slowly, step by step. At every point we need to carefully calibrate the conclusions of our reasoning to the real world. Ignore this at your peril!

Reason doesn't necessarily lead to insight. Unbridled reasoning is an unguided missile that can lead to flat-earthism and God-as-first-cause arguments. Reason only works when constantly kept in check by observations of the real world. Science no longer argues about the number of angels that fit on the head of a pin because nobody has ever seen any angels on the head of a pin. This kind of 'reasoning' was thrown out with the Middle Ages, and just as well.

As an unrepenting Popperian I say: go forth and falsify.

fG

boneyard bill

bd_from_kg writes:

But the naturalist has to assume that reason is valid in order to prove that reason is valid. That is, the naturalist must account for reason. But the naturalist can do that only by assuming the validity of reason in the first instance. Reason is not to be found in the naturalist's fundamental description of the world.

The theist also assumes that reason is valid but uses this as evidence of God's existence. For the theist, reason is a fundamental axiom. For the naturalist, nature is the fundamental axiom, and the validity of reason is something that has to be proven. But how do you prove this without assuming its validity to begin with?

You've changed the argument by insisting that Lewis' claims involve two separate arguments when they are really aspects of a single argument. You cannot separate Lewis' claims about the "rule" from his later point about inference. The point is that reason does not exist in the naturalist position. How can the naturalist get it in there? Only by an inferential process that assumes that reason is valid to begin with.

But how does the naturalist know this? Only through inference. How does he know his inferences are valid? He doesn't. He assumes this. But then isn't such an assumption among his fundamental axioms? This rather crucial assumption can't just be left dangling in mid-air.

It isn't a matter of question begging. It is a matter of having a coherent theory or not having one. Lewis' rule is not some archaic assumption. It asks how reason got into nature. The naturalist cannot explain this without recourse to inference. The naturalist must therefore postulate inference to prove it but must then omit the postulate from the argument. That does not add up to a coherent position.

[ January 22, 2002: Message edited by: boneyard bill ]</p>

99Percent

Reas&n and concept$alizatio* come( from the h*man brain's am@zing *bility to c+nnect-t!e-dots. It seems mag@cal at first and even gives thought to theisti- pos*ibilities, but ? t^ink it can be e**lained af^er all and m*ybe even r#produced wi@*h soph*sti_ated e*ough com&uters.

The world is perceived with an incredible amount of noise and interference. Our brains have evolved to develop natural mechanisms to filter out all this noise.

SteveD

I'm still waiting for someone to explain why the very logical process described by "Natural Selection" is considered "irrational".

Steve

boneyard bill

SteveD writes:

Perhaps non-rational would be a better term but most of the citations referred to use the term irrational. The naturalist holds that the world is governed by impersonal physical laws. These laws claim to describe how the world works. There is nothing in these laws that is logically compelling. We know that water flows downhill because it always has. But there is nothing in the term "water" that requires that it flow downhill. In fact, on rare occasions it does flow uphill, as in the Bay of Fundy where tidal action actually causes the water to flow upriver at certain times of the day. There is nothing logical about natural laws. They simply are what they are and it would violate no logical law if they were different.

Natural selection claims to explain how creatures, including humans, evolved from these non-rational processes. There is nothing irrational about the theory of Natural Selection. But the question is, can we trust our reason? If we can't then we can't put any stock in the theory of natural selection. But we have to trust our reason before we can arrive at the theory of Natural Selection. In other words, we have to presuppose the validity of reason before we can arrive at the naturalistic proof for that presumed validity, and as C.S. Lewis pointed out, a theory that assumes what it sets out to prove is "rubbish."

Kharakov

Probably because natural selection fanatics like to say that there is not intent or rational motive behind evolution. Although claiming that intent just all the sudden popped out of the blue seems to be irrational as hell.

Vorkosigan

"Natural selection fanatics" <img src="confused.gif" border="0">

Vorkosigan

CS Lewis has mis-stated the case, mistaking a positive feedback loop for a circular argument. It is a commonplace error. Read on...from an older post...

As far as my particular naturalist beliefs, I am an evolutionary naturalist. Human cognitive capacities are evolved capacities, just like those of other animals. It is undeniable that human abilities are well-adapted to the world in which humans function, and that these capacities are non-trivial. A fantastic amount of processing power is required just to walk or read a poem.

Empiricist philosophers have emphasized the role of perceptual experience in their analyses of knowledge because of the high degree of subjective certainty attached to such experience. The problem was then to get beyond this subjective experience. From an evolutionary perspective, there's a connection between subjective certainty and the objective reliability of our interactions with the world. Although the evolutionary history of some of these capacities for developing reliable perceptions of world is still in the dark, there's no denying the reliability of our perceptions.

Traditional rationalism has focused on these subjective intuitions we have, that space-time is 3D and that time is linear. These judgements seem to be built into the way we think. Indeed, they seem to be (see <a href="http://www.amazon.com/exec/obidos/ASIN/052148541X/internetinfidelsA/" target="_blank">Tools, Language and Cognition in Human Evolution</a>), since those aspects of the world relevant to our fitness have that structure. But rationalists, like empiricists, are still stuck with the problem of subjectivity.

Evolutionary theory provides an alternative. By looking back at their own evolutionary history, scientists can better understand their own cognitive situation and investigate the development of their own cognitive capacities. We know already that we have reliable perceptions about the world; the problem of induction is really not "how is it we can induct" but "how is it our inductions are so reliable?" The reply to Hume is contained in modern cognitive science, which has shown that inductive capacities are built into humans (and other animals). So are things like logic, the idea that things in the world have intentions, and so on. Most of these originate in the cognitive equipment necessary for competition in our highly developed social world. If you look at this <a href="http://www.psych.ucsb.edu/research/cep/primer.html" target="_blank">Primer on Evolutionary Psychology</a> you'll get a few simple examples of how logic (in that case, conditionals) operates in human social systems.

In other words, the cognitive view starts with the realization that our perceptions are largely reliable, wonders why this is so, and then uses the tools of science to discover why, confirming that indeed our perceptions our reliable.

Some of you I know are shouting "Hey wait! This is circular!" I would argue, as I think Wittgenstein did, that epistemology has been gripped by the idea that one must prove in Straight Lines. The philosopher reasons from first principles, then, grounded in A, moves on to B. The cognitive scientist starts with B and using B, goes back to find what A is all about. Circularity does not exist here, because at each iteration of the scientific process, something has changed: we have more knowledge about ourselves and the world. This is not circularity, but a positive feedback loop. Using our powerful cognitive abilities made reliable by evolution, we expand our knowledge of the world, thus understanding our own cognitive abilities better. This new knowledge enables us to better understand the world. And so on. As Giere noted in <a href="http://www.amazon.com/exec/obidos/ASIN/0226292061/internetinfidelsA/" target="_blank">Explaining Science : A Cognitive Approach(Science and Its Conceptual Foundations)</a> "the existence of these positive feedback loops is not a limitation that must be overcome by some special form of philosophical analysis. On the contrary, it is one of the things that makes modern science so powerful."

Hope this helps. In sum, we do not "presuppose" our cognitive processes produce effective reasoning abilities. We know this is true because we're still alive, despite the millions of interactions we have with the outside world each day. Instead, we use methods we know are effective to investigate why those methods are effective, and come at last to an understanding of why humans can reason so well.

Michael