Skip to content

C. S. Lewis and the “Argument from Reason”: An Examination and (Modified) Defense, Part III

August 20, 2012

III.             Unpacking the Extended Argument in Miracles

             In order to feel the weight (and the substance) of Lewis’s argument, we will necessarily have to trek with him through his terms, definitions, and steps.  As most philosophical arguments go, the entirety of the argument is built step by step from a common base of definitions.  For Lewis we must begin by explaining what we mean by “nature” and “Naturalism,” or in his words, what the Naturalist believes.



Lewis defines “nature” as that which “happens ‘of itself’ or ‘of its own accord’:  what you do not need to labour for; what you will get if you take no measures to stop it.”[1]  In other words, nature is that which “just happens.”  Now, admittedly, this may be a definition with which the naturalist disagrees with.  He or she might be more comfortable by saying that nature is that “which is”—or everything.  However, Lewis feels this evades the issue, for of course, the naturalist is going to define it such, since, for him or her, supernaturalism is ruled out ipso facto.  Thus Lewis attempts to arrive at a definition of nature that both naturalists and supernaturalists can agree upon.

Assuming that this definition is viable, Lewis then proceeds to explain what the naturalist believes.  Accordingly, he or she believes several things:  first, that the “ultimate Fact”—the thing that you cannot go behind (i.e. the Origin or First Cause or Event) is a process that is ‘going on of its own accord,’ or naturally.[2]  From the first event, every other particular event (like the fact that I am sitting here writing) is the direct result of a prior event, which is a direct result of a prior event, so on, and so on.[3]  Thus, spontaneity is outlawed by default, except of course, for the original event.  All events, being natural and derivative of the first Event, are causally linked to prior events, and ultimately to the first Event.  Being a book about miracles, Lewis points out that miracles, in such a view, are obviously impossible because an “outside” event from this interlocking system of causal connections is ruled out from the beginning.  For the naturalist, then, everything that is, occurs within a system of causally connected events going all the way back to the First Event, which itself occurred ‘of its own accord’ or “naturally.”  There is nothing that occurs that is not a result of this process.  From here, Lewis forges ahead to discuss the implications of Naturalism, and the major difficulty that emerges—the Argument from Reason.


Implications of Naturalism and The Argument

Though Lewis does not initially make the following implication, it does permeate his argument nonetheless.  This is the implication that in Naturalism, all that is, is physical—or matter.  Thus, for all intents and purposes, Naturalism and Materialism are coterminous.  Accordingly, everything that exists is a result of natural and physical processes.  Based on this view, Lewis argues that if Naturalism is true, “every finite thing or event must be (in principle) explicable in terms of the Total System.”[4]  That is, in principle[5] everything that occurs should be able to be reduced to a natural (and material) process.  The act of human thinking, then for the Naturalist, is ultimately the result of natural process—i.e. a series of chemical reactions in the human brain.

With the foundation that, for the naturalist, all events, including thinking events, are the result of material causes, Lewis argument proceeds thus:  for knowledge to be “valid,” [6] it must be the result of a certain kind of thinking.  To put it simply, it must result from a certain process of reasoning.  Lewis asks his readers to consider two senses of the word “because.”  The first sense is found in the following sentence: “Grandfather is ill today because he at lobster yesterday.”  The second sense is found in this sentence: “Grandfather must be ill today because he hasn’t got up yet (and we know he is an invariably early riser when he is well.”[7]  For Lewis, the first statement cannot be an act of genuine knowledge because it is a sheer fact of “Cause-and-Effect.”  Certainly it is true in the sense that it occurs, but it cannot be true in the sense that 2+2=4 or in the sense the law of gravity is true because scientists have done a great many measurements and then inferred that there is, indeed, an observable reality of gravity.  Rather, the first sentence is just a fact.

The second sentence’s sense of “because” however is the result of a genuine knowledge because it emerges through a process of reasoning.  Lewis calls this the “Ground-Consequent” sense, because “The old man’s late rising is not the cause of his disorder but the reason why we believe him to be disordered.”[8]  Put differently, the “ground” for why we believe Grandfather to be sick is based on the fact, or consequence of his sleeping in.  One does not just observe that ‘Granfather’ is sick; rather, one draws the conclusion based upon the available evidence and the inferences drawn from it.  This of course is an example of inductive reasoning; however, the same type of process would be true with an act of deductive reasoning.  In either case, the point is that for genuine[9] knowledge to occur, it must happen as a result of this process of reasoning and drawing conclusions.

If we can agree with Lewis (and we may not) up to this point, then according to him, we have a “cardinal” difficulty with naturalism.  For in naturalism, everything that occurs, does so in the “Cause-and-Effect” sense—even the “events” of thinking in our brains.  For, as we have mentioned, everything that occurs is a result of natural and physical (cause-and-effect) processes.  So if the “reasoning” that we do is ultimately not a result of the “Ground-Consequent” of “because,” but a result of a “Cause-and-Effect” physical process (i.e., chemicals moving in our brains) then our knowledge is not “valid” or, to use a more modest word, “warranted.”  Lewis therefore draws the following conclusion:

Unless our conclusion is the logical consequent from a ground it will be worthless and could be true only by a fluke.  Unless it is the effect of a cause, it cannot occur at all.  It looks therefore, as if, in order for a train of thought to have any value, these two systems of connection must apply simultaneously to the same series of mental acts…But unfortunately the two systems are wholly distinct.[10]

According to Lewis, this is devastating for Naturalism.  If “valid”—genuine—reasoning arrives only by a process of reasoning, and Naturalism is a theory that say thoughts are “events” that happen by physical causes, then Naturalism ultimately undermines or “disproves” itself.  For, Naturalism is a view about the way the world works that is reached by a process of reasoning.  Yet, this process of reasoning leads to a view of reality that posits that there is not genuine reasoning!  Again, it is like saying, “I reason that there is no reason.” And, it is for this reason that Lewis writes:  “It [Naturalism] offers what professes to be a full account of our mental behavior; but this account, on inspection, leaves no room for the acts of knowing or insight on which the whole value of our thinking as a means to truth, depends.”[11]

My own understanding of Lewis’ argument could be formulated as follows:

(i.)     Naturalism suggests that the thoughts I have are a result of natural processes—chemical reactions—in my brain.

(ii.)    As natural processes they are determined or “automatic”; they simply occur (as events).

(iii.)   By reasoning, we typically mean that process by which we make inferences based on information or premises to draw conclusions.  In other words, we take an active role (i.e. not  automatic) in our coming to “truth,” or knowledge.

(iv.)   It is through reason that we come to know something as true.

(v.)     Reasoning and Naturalism seem prima facie to be incompatible with one another.

(vi.)    Naturalism is a belief about the world that supposedly is arrived at through a process of reasoning.

(vii.)   Thus Naturalism is a conclusion, through a process of reasoning, that reasoning is impossible.  This, therefore, undermines Naturalism.

(viii.)  Thus, we have no ‘reason’ to believe Naturalism to be true, as it is self-defeating.

It would seem that Lewis has a slam-dunk case against Naturalism, but John Beversluis does not think so.  With that, we turn to his extensive rebuttal.

[1] Lewis, Miracles, 214.

[2] Ibid.

[3] Ibid.  Thus, for Lewis, to be a strict naturalist is to be a determinist.

[4] Lewis, Miracles, 217.

[5] Lewis maintains, that of course, the naturalist does not have to actually produce an explanation that is accurate, for this would be impossible being that scientific knowledge is progressive.  However, the naturalist must maintain that “in principle” every event can be explained naturally, 217.

[6] The philosophical term is “warranted” or “justified” belief.

[7] Miracles, 219.

[8] Ibid.

[9] The debate on what constitutes as “warranted” belief among epistemologists far outweighs the current discussion.  I think it is safe to conclude that however one arrives at knowledge, it is more valuable to have done so through a process of reasoning.

[10] Ibid.

[11] Miracles, 220.

One Comment leave one →
  1. November 14, 2013 8:05

    We arrive at our conclusions from what looks like a rational process.

    However, mechanistically, those processes are mere chemical / electrical / naturalistic reactions in our brains.

    Since these are nonrational processes, how can the conclusions we derive be rational?

    Of course, there is much to be said about emergentism – the idea that properties can emerge from a network which appear greater than the sum of their parts (think of the patterns flocks of sparrows can cause etc). Many people use this theory to explain consciousness.

    The problem with people like yourself, is that you define reasoning in a functional way:

    “This of course is an example of inductive reasoning; however, the same type of process would be true with an act of deductive reasoning. In either case, the point is that for genuine[9] knowledge to occur, it must happen as a result of this process of reasoning and drawing conclusions.”

    But, of course, computers can do this. This is the aim of worked in Artificial Intelligence. The problem, historically, with AI workers is they started with blank slates. But we are born with inbred programming which means we are HUGELY far away from being blank slates.

    We are programmed in much the same way computers are, through evolutionary psychology. See Steven Pinker’s excellent “How The Mind Works” for a hugely comprehensive idea of this, or even the book I am presently reading, called Incognito.

    As my theistic friend said the other day in the staff room, if this really is evidence that God exists, then it’s pretty crappy (I inferred this from his comments) because everything we know about psychology is that we have also evolved many ways which render this process ‘irrational’ or biased or unreliable. There are some 60 cognitive biases, for example.

    Here is the entry on deduction and inductive reasoning for the AI entry on wiki:

    Deduction, reasoning, problem solving[edit]
    Early AI researchers developed algorithms that imitated the step-by-step reasoning that humans use when they solve puzzles or make logical deductions.[39] By the late 1980s and 1990s, AI research had also developed highly successful methods for dealing with uncertain or incomplete information, employing concepts from probability and economics.[40]
    For difficult problems, most of these algorithms can require enormous computational resources – most experience a “combinatorial explosion”: the amount of memory or computer time required becomes astronomical when the problem goes beyond a certain size. The search for more efficient problem-solving algorithms is a high priority for AI research.[41]
    Human beings solve most of their problems using fast, intuitive judgements rather than the conscious, step-by-step deduction that early AI research was able to model.[42] AI has made some progress at imitating this kind of “sub-symbolic” problem solving: embodied agent approaches emphasize the importance of sensorimotor skills to higher reasoning; neural net research attempts to simulate the structures inside the brain that give rise to this skill; statistical approaches to AI mimic the probabilistic nature of the human ability to guess.

    We bypass the conscious parts of the reasoning process simply because our brain would melt if we didn’t (again, see Incognito on this).

    So, amusingly and problematically for Lewis and yourself, it appears that we are NOT rational, after all. We bypass rationality with intuition and post hoc rationalise that judgement. But that rationalising is merely a function that AI can, or theoretically could, do. It is about making connections (I am a teacher, and this is the key to learning as well as rationalising).

    Essentially, the argument from reason is very problematic.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: