Wednesday, October 04, 2006

Lewis's Last Version of the Argument from Reason

The Discarded Image was published posthumously.

No Model yet devised has made a satisfactory unity between our actual experience of sensation or thought or emotion and any available account of the corporeal processes which they are held to involve. We experience, say, a chain of reasoning; thoughts, which are ‘about’ or ‘refer to’ something other than themselves, are linked together by the logical relation of grounds and consequents. Physiology resolves this into a sequence of cerebral events. But physical events, as such, cannot in any intelligible sense be said to be ‘about’ or to ‘refer to’ anything. And they must be linked to one another not as grounds and consequents but as causes and effects—a relation so irrelevant to the logical linkage that it is just as perfectly illustrated by the sequence of a maniac’s thoughts as by the sequence of a rational man’s.” C. S. Lewis, The Discarded Image: An Introduction to Medieval and Renaissance Literature (Cambridge: Cambridge Univ. Press, 1964), 165-6.

22 comments:

Anonymous said...

"And they must be linked to one another not as grounds and consequents but as causes and effects—a relation so irrelevant to the logical linkage"

Did Lewis ever fully explain
a) how logical relations are linked and
b)how cause and effect are linked?

If not, how can he speak with such authority regarding the incompatibility of grounds and consequents with cause and effect?

Victor Reppert said...

Logical relations, at least those of strict entailment, are linked by absolute necessity. They not only do exist, them must exist, and they exist in all possible worlds. The cause and effect relations in this world exist contingently. The could be otherwise. So the reduction of logical relations to cause-and-effect relations seems to me to be doomed from the start.

Anonymous said...

So you are saying that people who use logic never make mistakes? Their logical decisions follow necessarily?

Even a simple adding machine can be set up to always produce 6 when 3 is added to 3. That is an encoding of a logical relation within a cause and effect system.

Sorry, but I still fail to see why there is this supposed incompatibility between logical relations and cause and effect relations.
Not to mention that there is still no explanation of what a cause and effect relation really is. Or what a logical relation really is.

Victor Reppert said...

In rational inference, as Lewis says, one thought follows another thought not by being, but by being seen to be a ground for it. The relation is necessary, even though the perception may or may not take place. 2 + 2 = 4 is true yesterday, today, and forever, in all possible worlds. How do we know this?

Anonymous said...

"In rational inference, as Lewis says, one thought follows another thought not by being, but by being seen to be a ground for it."

Looks to me like a mere description of how ratinal inference is expereinced by humans. No explanation of how it works.
Sorry, but I fail to see anything you've said so far that would support Lewis' rather bold claim.

Could you start with defining cause and effect and explaining how it works?

Anonymous said...

(Other) Anonymous,

Could you start with defining cause and effect and explaining how it works, so that we may skip Victor giving you a definition and explanation that you might reject. (If, however, you have no definition and explanation yourself, not even a tenuous one, then why debate this with you since you don't even understand it?)

Anonymous said...

To the other anonymous. I don't think anyone has been able to define and explain cause and effect adequately. That was the point of my question. Can you provide one?
Lewis' claim appears to me to be based mainly on ignorance ( of cause and effect, among other things) and lack of imagination.

Victor Reppert said...

A naturalistic world view, as I have defined it in my bood, has three features. 1) The physical system of events is causally closed. 2) The physical system of events is mechanistic--all causes within that system are non-purposive and non-rational, and 3) all other facts about reality supervene on the physical facts, such that, if those physical facts obtain, then all other facts must be the way they are. In such a mechanistic universe, is it possible to perform an action, or hold a belief, for a reason. Is it possible for one's perception that the Pythagorean theorem is true cause you to lay out your garden in a certain way? Regardless of how cause and effect is defined, given the fact that it all causal relations must in the last analysis be mechanistic, it seems we have a prima facie argument against the possibility of rational inference emerging in this kind of a universe. But in order for science to exist, we have to have performed some rational inferences, therefore the very existence of science goes to show that naturalism can't be true.

Anonymous said...

You still have not provided any explanation for how rational inferences work. How is it possible for beings like us to make rational inferences?
And again, no definite presentation of what you think cause and effect are and how causation works. There is a lot of controversy over causation in philosophy. I get the impression you are simply relying on the man in the street"s view of causation.

Anonymous said...

(Other) Anonymous,

I want to be sure I understand what you are saying. Are you saying that Lewis is ignorant of something everybody is ignorant of? And are you saying that nobody knows what causation is? Are you also saying that you see no difference in coming to believe that A equals C (the effect) because you know that A equals B and B equals C (the cause) in contrast to a window being broken (the effect) because a stone was hurled (the cause)?

By the by, I know enough about causation to know that my mind (and will) is free in a way that a stone is not (at least that's what the man on the street told me).

Anonymous said...

"Are you saying that Lewis is ignorant of something everybody is ignorant of?"

Philosophers and scientists have been struggling for a long time to understand what causation actually is.
Lewis and Victor are claiming that rational inference cannot occur in a cause and effect system: something from the outside, that is free of cause and effect, is needed for rational inference. To make a persuasive argument they need to lay out what cause and effect actually is and how it works and the same for rational inference.


"By the by, I know enough about causation to know that my mind (and will) is free in a way that a stone is not (at least that's what the man on the street told me)."

And a brain is different from a stone. So what else is new? I don’t see how your statement addresses the real issues here.

Ironically and unfortunately, in their efforts to discount naturalism I think both Lewis and Victor are practicing bad theology: they are both trying to claim that they know how God actually created the world. They are both, in effect, saying that God could not have created a physical world which was capable of evolving creatures with rational inference. Interestingly, I come away with the opposite view when pondering over the early chapters of Genesis.

Anonymous said...

(Other) Anonymous,

Neither Lewis nor Victor ever said that rational inference is not a sort of causation.

I think you missed the point of my other comment. If I drop my brain it will fall like a stone too. But thinking is different from falling. If this much is not admitted then we're simply in disagreement.

In what ways does Genesis suggest that consciousness evolved?

Anonymous said...

"Neither Lewis nor Victor ever said that rational inference is not a sort of causation."
If so, then that just reinforces my point regarding the need to present an explanation of cause and effect and an explanation of how rational inference works.


"I think you missed the point of my other comment. If I drop my brain it will fall like a stone too. But thinking is different from falling."
And a brain is different from a stone. Sorry, I don't see your observation of a difference here as providing support for Lewis' claim. I find it strange that people think that by pointing to a falling stone they are providing support for the claim that a brain is not able to make rational inferences.


"In what ways does Genesis suggest that consciousness evolved"
To be precise, I said: "a physical world which was capable of evolving creatures with rational inference".
Genesis susggests that God created a self sufficient world. A structured and uniform one. A lawful world. Because of that uniformity in it's laws, science has been able to make the progress it has in understanding how things work in this world.
Obviously, a self-sufficient world can be used by an atheist to support his atheism. And it also appears obvious that Lewis and Victor are troubled by that. But their argument results in a diminishment of God's powers.
By the way, I think it as meaningful to say God is conscious as to say He has an arm. Both are to be taken metaphorically.

Anonymous said...

(Other) Anonymous,

There can be no discussion here if you do not allow that thinking is different from falling.* If you do not allow that, then, as I said, we are simply in disagreement, and we should move on. Your positon on this, as provided in your last comment, was unclear to me. Could you please state it outright.

If you didn't mean that Genesis suggests that consciousness evolved, then I just misunderstood you and therefore (as I'm assuming, then, that you don't think Genesis suggests that consciousness evolved, since you corrected me on that) we don't disagree there.

*(For clarification: Though I think it should be obvious, I am not simply meaning to ask whether you agree that thinking and falling are different in that thinking is thinking and falling, failling--that is, that they're not the same thing. That is not what I'm asking, though that much should be obvious. If, however, what I am meaning to ask is not entirely clear to you, then please say so and I will attempt to clarify.)

Anonymous said...

"*(For clarification: Though I think it should be obvious, I am not simply meaning to ask whether you agree that thinking and falling are different in that thinking is thinking and falling, failling--that is, that they're not the same thing. That is not what I'm asking, though that much should be obvious. If, however, what I am meaning to ask is not entirely clear to you, then please say so and I will attempt to clarify.)"

Thanks for the clarification. It tells me that I really don't think I understand what you mean by thinking being different from falling. To me it is obvious that they are different activities. Just as flying is a different activity than walking.
For me thinking is as grounded in the laws and properties of the universe as falling is. That seems quite consistent with my view that God intended to create a self-sufficient world.
But you seem to be trying to say something else?

Don Jr. said...

(Other) Anonymous,

Sorry it took me so long to reply. I've been busy and forgot about this discussion (hopefully you haven't).

I will see if we agree on any basics first, so that discussion might be possible. It seems to me that the physical world is mechanistic. This is indicated, I think, by the fact that, for instance, gravity is constant, energy is conserved, and so on, that is to say, by the fact that we have what we call "laws of physics"--some call them "laws of nature," but that can be misleading, for then they sometimes suppose that Nature (now with a capital 'N') made them.

Thus when a stone is dropped it will always fall. Or when a man walks, he will always walk on ground. And if there is no ground to walk on then, like the stone, he will fall. This is meant to say that the physical world is mechanistic or, in other words, deterministic. Thus a man can set up a row of dominoes and know that if he hits the first domino the last one will fall; and, if he calculates it, he will know that it will fall in a certain way, at a certain time, landing at a certain place, i.e., there is only one possible outcome. Of course one may intervene and disrupt the process, but the physical world, when left to itself, is deterministic. Do you agree with this?

Anonymous said...

Generally speaking I would agree with this. I would quibble over your use of the word "know" in your domino example. Perhaps more accurate to replace it with something like "very confident." And I don't particularly care for "physical world" rather than just plain old "world."
I also imagine that we are going to run into different understandings of the words "mechanistic" and "deterministic." For example, the activities of a cell are mechanistic but it would be silly to try and say that it is mechanical in the way that a watch is. Or that quantum level mechanics is mechanical in the way that the activities of a cell are.
And as I understand it, " to determine" is not much different than "to enable." When something determines something else, it enables it. To use your domino example: it becomes possible for the man to knock over the last one by pushing over the first domino. And the same sort of determinism enables the man to decide whether or not to push over that first domino.
And to repeat what I said earlier, this all seems to me to be quite consistent with the view that God created a self-sufficient, uniform world: one that doesn't require His intervention or some sort of supernatural tweaking to keep it going.

Anonymous said...

(Other) Anonymous,

I think we agree enough on this to proceed. Do you think that the nature of the (physical) world, as we have somewhat agreed upon, also exists in the mental realm. (Sorry to keep using the term "physical world" but I think it is a necessary for clarification. When I say "physical world" I mean a world, or section of the world, devoid of any thinking agents--objects in space, for example.) So for instance, scientists, knowing the needed details can know (at least roughly) when an eclipse will occur, or at what angle and with what speed to swing the shuttle around the moon so that it will be shot back to Earth, and so on (there are an endless number of other examples).

Now, is this the case when thinking agents are involved? Can a scientist be sure of what I will be doing next year? He may be sure of my age but what about my choices and thoughts? Knowing what I am now thinking will he be able to know what I will be thinking in 20 years? In short, do you also think that the "mental world" is somewhat deterministic?

Anonymous said...

As I've already indicated, the behavior of the brain is in accordance with the laws and properties of the world. As far as I am aware, the brain is a mechanistic, deterministic system like all systems appear to be in this world. And I think most scientists would agree that the brain is the organ in the body that does the thinking, though the other organs (like the endocrine system) have a big impact on the functioning of the brain.
But bear in mind that I think we most likely have quite different ideas of what the abstract concepts "mechanisitic" and "deterministic" mean. For instance, I have trouble seeing how it would be possible for anyone to think rationally outside of a deterministic system. I think all reasoning is ultimately of an inductive nature. And induction could only work in a uniform or deterministic system.
To be honest, I am a little puzzled by your approach here. It seems to be more in line with the traditional free will apologetical approach.
Why does determinism appear to you to have a negative impact on the ability of a sentient creature to make rational inferences?

Anonymous said...

(Other) Anonymous,

Thanks a lot for your reply. I think we just differ here because it doesn't appear to me that my thoughts are determined by anything external to me (whereas a rock is determined, by the laws of physics, to fall).

The reason I think determinism is inimical to rational inference is because it does not appear to me that the laws of physics in accordance with the state of my brain at a certain time determines what I will think at a later time. We, I think, tend to call someone reasonable because they have come to a conclusion themselves, not because they were deteremined by the laws of physics and an earlier state of their brain (or really the universe) to hold such and such a belief at such and such a time.

Note: None of the above is given as an argument. I'm merely citing what appears to be the case to me and noting that you view otherwise. I am making no argument for my case though. If you are looking for an argument, I would suggest some of C. S. Lewis's work (his Miracles, for instance; but he also has a number of short essays defended the same thesis) and Victor Reppert's C. S. Lewis's Dangerous Idea (which is a lot clearer than I have been).

Anonymous said...

"(Other) Anonymous,

Thanks a lot for your reply. I think we just differ here because it doesn't appear to me that my thoughts are determined by anything external to me (whereas a rock is determined, by the laws of physics, to fall)."

Laws of physics are descriptions of uniformity in this world. The laws themselves are incapable of determining anything, they have no power or force. We have such laws because we observe uniformities in this world.
Also, I think that many of our thoughts are determined (at least indirectly) by external factors like our language, culture and the genetic heritage. A person with downs syndrome is going to have limitations placed on their thoughts that a person with a "normally" developed brain would not have.

"The reason I think determinism is inimical to rational inference is because it does not appear to me that the laws of physics in accordance with the state of my brain at a certain time determines what I will think at a later time. We, I think, tend to call someone reasonable because they have come to a conclusion themselves, not because they were deteremined by the laws of physics and an earlier state of their brain (or really the universe) to hold such and such a belief at such and such a time."

I would call someone reasonable if I found that the conclusions they arrived at appeared reasonable to me. If, for example, someone told me that they opened their umbrella because it had started to rain I would call that reasonable behavior. I don't see what difference it would make whether their reasoning was determined or non-determined. Though, to be honest, I have trouble understanding how they could have arrived at their conclusion without some determinating factors. If the brain were a non-deterministic system I don't see how it could possibly engage in any kind of coherent behavior like reasoning.

"Note: None of the above is given as an argument. I'm merely citing what appears to be the case to me and noting that you view otherwise. I am making no argument for my case though. If you are looking for an argument, I would suggest some of C. S. Lewis's work (his Miracles, for instance; but he also has a number of short essays defended the same thesis) and Victor Reppert's C. S. Lewis's Dangerous Idea (which is a lot clearer than I have been."

I have read the above. Perhaps some of my comments here indicate why I am not persuaded by their arguments. Fortunately one can still be a Christian theist and not find their arguments to be persuasive.
Thanks for the interesting discussion.

Anonymous said...

Fortunately one can still be a Christian theist and not find their arguments to be persuasive.

Agreed.