Wednesday, July 12, 2006

The Concept of Naturalism

This is familiar to most of you, but I am including it in a paper I am writing.

The Concept of Naturalism
Exactly what does Lewis mean by naturalism? Very often the terms Naturalism and Materialism are used interchangeably, but at other times it is insisted that the two terms have different meanings. Lewis says,
“What the naturalist believes is that the ultimate Fact, the thing you can’t go behind, is a vast process of time and space which is going on of its own accord. Inside that total system every event (such as your sitting reading this book) happens because some other event has happened; in the long ru, because the Total Event is happening. Each particular thing (such as this page) is what it is because other things are what they are; and so, eventually, because the whole system is what it is.”22
As a presentation of naturalism, however, this might be regarded as inadequate by contemporary naturalists, because it saddles the naturalist with a deterministic position. The mainstream position in contemporary physics involves an indeterminism at the quantum-mechanical level. Lewis himself thought that this kind of indeterminism was really a break with naturalism, admitting the existence of a lawless Subnature as opposed to Nature, but most naturalists today are prepared to accept quantum-mechanical indeterminism as part of physics and do not see it as a threat to naturalism as they understand it. Some critics of Lewis have suggested that his somewhat deficient understanding of naturalism undermines his argument. Lewis, however, insisted on “making no argument” out of quantum mechanics and expressed a healthy skepticism about making too much of particular developments in science that might be helpful to the cause of apologetics.23
However, contemporary defenders of the Argument from Reason such as William Hasker and myself have developed accounts of materialism and naturalism that are neutral as to whether or not physics is deterministic or not. Whatever Lewis might have said about quantum-mechanical indeterminacy, the problems he poses for naturalism arise whether determinism at the quantum-mechanical level is true or not.25
Materialism, as we understand it, is committed to three fundamental theses.
1) The basic elements of the material or physical universe function blindly, without purpose. Man is the product, says Bertrand Russell, of forces that had no prevision of the end they were achieving. Richard Dawkins’ exposition and defense of the naturalistic world view is called The Blind Watchmaker: Why the Evidence of Evolution Reveals a World Without Design26 not because no one ever designs anything in a naturalistic world, but because, explanations in terms of design must be reduced out in the final analysis. Explanation always proceeds bottom-up, not top-down.
2) The physical order is causally closed. There is nothing transcendent to the physical universe that exercises any causal influence on it.
3) Whatever does not occur on the physical level supervenes on the physical. Given the state of the physical, there is only one way the other levels can be.
The argument from reason is concerned with what philosophers today call prepositional attitudes, states such as believing that proposition p is true, desiring that proposition p be true, doubting that proposition p be true, etc, and how these prepositional attitudes come to be caused. There are three types of materialism, at least so far as propositional states are concerned. One type is called eliminative materialism, which argues that propositional attitudes like belief and desire do not exist. Another kind is called reductive materialism, according to which mental states can be analyzed or reduced in physical terms. A third kind is non-reductive materialism, according to which mental states are not to be analyzed in physical terms, but given the state of the physical, there is only one way the mental can be. All of these positions are consistent with the definition of materialism given above.
As for naturalism, it is hard to see how a world-view could be naturalistic without satisfying the above definition. Perhaps a world could be naturalistic if there was no matter or if the science describing the most basic level of analysis is not physics. However, whatever objections there might be to materialism based on the argument from reason would also be objections to these forms of naturalism. So although the argument is primarily directed at materialism, so far as I can tell, there is no form of naturalism that fares any better against the argument from reason than materialism.


Mike Wiest said...

I don't think "naturalism" as you have so clearly defined it here actually applies to quantum theory, because:

1. The quantum theory is not causally closed. Not only are there apparently random outcomes of particular "measurements," but the specific measurments and their timing are undetermined by the theory. In practice a human experimenter is assumed to have a free choice of measurements to make (free in the sense of not determined by the theory). Stapp makes a case that this allows us the reintroduce a causally efficacious mind into science.

2. A quantum system does not evolve "blindly...with no prevision of the end." This may be seen in elementary examples of electrons going through two slits at the same time before deciding where to land in a way that accords with the statistical interference pattern. Such "prevision of the end" is more transparent in Feynman's path integral formulation of quantum mechanics, in which a system literally considers every possible path it might take before choosing one which will be "optimal" in the technical sense of minimizing the system's action over time. One might interpret "minimizing the action" as the "goal" of physical systems. Note that this is not a trivial sense in which I could attribute a goal to any determined activity. The theory does not work unless we assume that the system (in particular its wave function) objectively represents the objective possibilities and chooses among them.

In my view a quantum theory of the brain and mind might solve some of "naturalism's" problems with mind. I'm not claiming however that this step somehow automatically answers the argument from reason. But if neurobiologist consciousness theorists gradually accept, as I believe they will have to, that 19th century physics is not applicable to the fine dynamical organization of the conscious brain, the debate between naturalists and antinaturalists will get more confusing unless you refine the definition of "naturalism."

Now, one way I've heard "physicalism" defined is as a theory that does not admit any fundamental irreducible mental properties into the basic ontology. This might allow a clean distinction between physicalist and non-physicalist theories. But this debate might be orthogonal to the theist vs atheist debate that I think you are more interested in...

Martin Fracker said...

I am an experimental psychologist rather than a physicist or a philosopher, but I recall from a graduate level philosophy of science course that indeterminism in quantum mechanisms grew out of a measurement problem; namely, that we cannot measure a quantum process without changing it. While some people had indeed interpreted this indeterminism as evidence that determinism was false, such a conclusion goes beyond the evidence. The fact that we cannot measure a process without changing it does not refute determinism; rather, it follows logically from it.

I was also struck by the anthropomorphism of the notion that quantum processes make choices. I suppose one can speak of a probabilistic process as "choosing", just as one may speak about the moon "smiling" on a pair of lovers. But this is poetry and must not be mistaken for either logic or science. Quantum processes, as I understand them, are probabilistic which means that there is some underlying probability distribution that controls their outcome. Some theorists working in the area of deterministic chaos think of the mean of a probability distribution as an attractor. And I have seen at least one demonstration that collecting a large number of results from a certain deterministic but chaotic process leads to something nearly indistinguishable from a Gaussian probability distribution. Probability distributions, it seems, are at their root deterministic.

My point in all this is simply that quantum mechanics should not be taken as evidence against determinism.

Another question I would like to address is whether determinism invalidates human reasoning as a means of getting to the truth. I would like to tackles this question by means of a thought experiment. Suppose that I program a computer to answer "yes" to every question. I ask it if it is a computer, and it answers "yes". I ask it if it is a cow, and again it answers "yes". Obviously, the computer's answer to both questions is meaningless even though the first was accidentally correct.

Now suppose I change the computer's program so that it will answer "yes" sometimes and "no" sometimes based on the value of some random variable arising from an arbitrary probability distribution. Will the computer's answer have become any more meaningful? Obviously not. More variable, but not more meaningful.

Finally, imagine that I impose a variety of constraints and conditions on the function that transforms the value of the random variable into a yes or no answer. Would the computer's response now be any more trustworthy an indicator of truth? The answer is no, because the computer's response is still determined by the function I created and not by whether the response is actually true. It may be the case that the computer's response is sometimes correct just be accident, and the frequency of these responses may either increase or decrease as I impose additional constraints. But unless we have some independent means of knowing what the truth is, we will never know which of the computer's responses are true and which are false.

As this thought experiment shows, if determinism is true, then we cannot know which of our thoughts are true and which are false. Therefore, we cannot know that determinism is true. Consequently, it seems clear that the statement "I can be certain that determinism is true" is self-contradictory. Determinism might be true, but we cannot know that it is true.

R. Sreenivasan said...

That there is a creator.

A proposition is true when it holds true for all conditions within the tenets of its existence. Even if a single case exists against that proposition, we conclude that the proposition is false. Thus,this forms the basis for scientific naturalism.

The three axioms of scientific naturalism that we know are 1. The human mind is capable of accurately modeling all observable aspects of nature. 2. That an event or an object does not have a supernatural significance. 3. Scientific laws are adequate to account for all phenomena.
It is enough if we demonstrate that the axioms of scientific naturalism fails with simple illustrations.

Proof of a Creator
Let us examine the first axiom of naturalism, “The human mind is capable of accurately modeling all observable aspects of nature”. This axiom fails when we try to comprehend the origin of Universe. The Universe does not have a beginning nor does it have an end. Even with the Big Bang model, nobody can explain from where the point or singularity came from. Thus, it is impossible for the human mind to model the Universe in its entirety.

The second axiom of naturalism states, “That an event or an object does not have a supernatural significance.” Without complicating, let us take two aspects of a human being namely the vision and audition. We have to remember, that if fossils serve as evidence for evolution and Neo-Darwinism, then there must be scientific evidences for the two aspects vision and audition. As we know, the retina in our eye converts light into electrical signals. There is not even a simplest of example in nature from a non-biological source, which exhibits this property. We don't have a light detector in nature. The same holds good for audition. There is no example or evidence for a simplest of device that can convert sound into electrical signals. To put an end to any further arguments, let us examine if there exists any non-biological source that contains the monomers and polymers found in biological structures. We know that none exists. This lack of existence also serves as a proof.

It is impossible to model the origin of Universe with physical laws. As said earlier, the beginning and the end of Universe is not bound by time. This indicates the failure of the third axiom of scientific naturalism.

Write to me through sreeni.mail [at]


R. Sreenivasan said...

A small typo with my mail id. Kindly write your comments to
rsreeni.mail [at]

Sorry for any trouble caused