Naturalism and falsifiability

Metaphysical naturalism is the position that the natural universe is all that exists, and a common corollary of adherence to naturalism is a subsequent adherence to physicalism—the theory that everything that exists is reducible to the material or physical. Such a metaphysical jump seems warranted: if the natural world is all that exists, and the natural world contains only the physical, then everything that exists is physical. These inferences illuminate exactly why naturalists are so enamored with science. For if all that exists is physical, and science studies the physical (empirical) world, then science surely must be the be-all and end-all road to knowledge and inquiry.

However, while the partnership of science and naturalism might seem like a match made in (non-existent) heaven, it quickly becomes riddled with problems. First, remember that science is very strictly committed to the doctrine of falsifiability. That is to say, something is considered to be a valid scientific hypothesis or theory if it could, at least in principle, be proven false. But, how does this view of falsification jive with naturalism? That is to ask, is naturalism itself falsifiable?  Well it might seem at first glance that this is indeed the case. For all one needs is evidence of the supernatural, and naturalism would subsequently be rendered invalid, right? Well, maybe not. Let’s examine a discussion between naturalist Richard Dawkins and Cardinal George Pell that illuminates where I’m going:

Moderator: What would it take [to convince you of the supernatural]?

Dawkins: I used to think that if somehow a great big giant nine-hundred foot high Jesus with a voice like Paul Robeson suddenly strode in and said “I exist, here I am.” Umm, but even that I actually sometimes wonder whether that would…

Pell: I would think you were hallucinating.

Dawkins: Exactly, I agree. I agree.

The point of this exchange is the following. Regardless of the fashion in which the supernatural (if it exists) would expose itself, such exposure could always be explained away in terms consistent with naturalism and physicalism. For instance, if Jesus or God were to appear to me, or to the whole world, this could always be waved away as a hallucination, or a prank by a higher life form in the universe. Now obviously the validity of such theories would be highly implausible, although the naturalist could claim that the opposite—that the supernatural was actually manifest—is equally implausible. Nevertheless, the point remains that naturalism is still salvageable despite apparent evidence to the contrary.

This all means one important thing: naturalism is, at least in principle, not falsifiable. I stress “in principle” because I believe that most logical people would abandon naturalism in practice were the aforementioned events to take place. However, my focal point here is principle. Now, since naturalism is unfalsifiable, then naturalism is unscientific, for remember that science only deals with the falsifiable. But this leads to a perfect irony. For if naturalism and physicalism are true then science and empirical observation are our only source of knowledge. Yet, because of such empirical considerations naturalism itself must be rejected. Thus stated, empiricism and naturalism do not pair together as well as is commonly claimed.