Finding the Right Naturalism in Science

You have probably all heard how religion is the enemy of science. Let me say something you may not have heard: Naturalism represents an equally dangerous foe for the scientific enterprise. How can that be, you ask? Science is a naturalistic enterprise, isn’t it? Well, yes and no. Science is what we call methodologically naturalist in that it “assum[es] naturalism in working methods, without necessarily considering naturalism as an absolute truth with philosophical entailments.”[ref]Naturalism (Wikipedia)[/ref] Hence the old recognition that science cannot answer all of our questions as human beings, nor did it ever intend to. However, there are those who take naturalism beyond the realm of science and into the metaphysical[ref]I use the following definition of metaphysical: “of or relating to the transcendent or to a reality beyond what is perceptible to the senses” from Merriam-Webster. Metaphysics thus consists of anything non-empirical in character. Since naturalism most often entails the view that every claim must be empirically verifiable, naturalists generally reject the whole of traditional metaphysics, committing it “to the flames” as Hume famously declared.[/ref], stating that nothing exists beyond our physical world. They are known unsurprisingly as metaphysical naturalists.

Since science is methodologically naturalist, it has become natural (pun intended) for many metaphysical naturalists to adopt science as their standard of belief. In keeping with that adoption, many naturalists see it as their duty to defend science against the supernatural. I contend that naturalists, in trying to defend science, threaten instead to introduce the evils of the worst religious orthodoxy into science. I believe this outcome can occur for two main reasons:

First, many naturalists substitute science as their source of metaphysical belief since they lack any metaphysical claims of their own aside from rejecting all metaphysical claims. People are generally resistant to their beliefs being challenged, and so if people’s metaphysical beliefs are inextricably tied to their scientific beliefs, they are going to be much more dogmatic about scientific theories. And where, for example, a Christian might be content to simply reject science, leaving himself or herself sadly bereft of scientific knowledge but science itself fine, the naturalist, deriving their knowledge from science alone, has no choice but to try and warp science into not just an empirical expression but a metaphysical one as well–an orthodoxy about the nature of existence. This orthodoxy most often takes the form of believing that all reliable human experiences and knowledge must be reducible to an empirical level. Naturalistic orthodoxy strikes at heart of science itself by trying to make science into the new orthodoxy and thereby destroy the questioning and theorizing that makes the scientific enterprise possible.

The signs of this orthodoxy are clear enough in how people speak about science. We may rightly say that scientific theories are well-tested and highly explanatory. We may not say they are proven or true, and yet many people choose these exact words. I cannot state this point emphatically enough. Anyone who says science proves theories is making an anti-scientific statement. Karl Popper, the famous philosopher of science, played a large role in asserting this view of science:

Scientific theories, for [Popper], are not inductively inferred from experience, nor is scientific experimentation carried out with a view to verifying or finally establishing the truth of theories; rather, all knowledge is provisional, conjectural, hypothetical—we can never finally prove our scientific theories, we can merely (provisionally) confirm or (conclusively) refute them; hence at any given time we have to choose between the potentially infinite number of theories which will explain the set of phenomena under investigation. Faced with this choice, we can only eliminate those theories which are demonstrably false, and rationally choose between the remaining, unfalsified theories. Hence Popper’s emphasis on the importance of the critical spirit to science—for him critical thinking is the very essence of rationality. For it is only by critical thought that we can eliminate false theories, and determine which of the remaining theories is the best available one, in the sense of possessing the highest level of explanatory force and predictive power.[ref]Karl Popper and Growth of Human Knowledge (Stanford Encyclopedia of Philosophy)[/ref]

My pronouncement may seem like a semantics game–people conceivably could use ‘proven’ as shorthand for the much bulkier ‘well-tested and highly explanatory’–but I believe a view more worrying is at play when people state, “Science has proven this theory.” They are using science not as an expression of our current best understanding of the natural world, but as the only understanding they believe we will ever have about existence.

Believing science has shown us the only true understanding of the world leads to yet another problem: People begin to conflate accepting scientific conclusions as a measure of how well you understand science. Since science is the truth, if you do not accept it, that must mean you simply do not understand it. This is another anti-scientific attitude. As Dan Kahan rightly points out in the comments sections of his “Cultural Cognition” blog[ref]How religiosity and science literacy interact: Evolution & science literacy part 2. (The Cultural Cognition Project at Yale Law School)[/ref], a brief study of scientific history reveals the necessity of decoupling understanding theories from accepting theories in order to produce new scientific theories. Dr. Kahan cites how Einstein needed to understand and yet reject Newtonian physics to come up with relativity, just as proponents of quantum physics needed to understand and yet reject relativity to come up with quantum physics. Orthodoxy does not allow you to decouple understanding and acceptance: If the final truth has been discovered, you only reject it for lack of understanding.

Second, for some naturalists, their strongest commitment is to naturalism, not science, and therefore they will be highly opposed to any scientific theory that conflicts with naturalism or gives credence to supernatural claims. A good example of this point is the Steady State Theory. Steady State Theory was a popular theory in the early to mid 20th century and stated that the universe has always existed, in contrast to the Big Bang theory which has a clear beginning of the universe. As PBS puts mildly, “[t]his struck a philosophical chord with a number of scientists, and the steady-state theory gained many adherents in the 1950s and 1960s.”[ref]Steady-State Universe (PBS.org)[/ref] The theory was only abandoned after a long struggle and discovery of strong falsifying evidence in part due to the popular philosophical implications of the theory among naturalist scientists.

To be fair, problems can and have arisen when scientific theories conflict (or seemingly conflict) with supernatural claims. My point here is not to set up a competition between supernaturalism and naturalism over who is the “true” defender of science. Neither group is. The true defender of science is anyone who recognizes that any orthodoxy is a threat to the scientific enterprise. Thus Karl Popper invites us all to become defenders of science, not by what particular metaphysical beliefs we hold or reject, but by upholding this opposition to orthodoxy in our quest for greater understanding of the world in which we live:

I hope that my proposals may be acceptable to those who value not only logical rigour but also freedom from dogmatism; who seek practical applicability, but are even more attracted by the adventure of science, and by discoveries, which again and again confront us with new and unexpected questions, challenging us to try out new and hitherto undreamed-of answers.[ref]The Logic of Scientific Discovery. Karl Popper. 1958.[/ref]

As a final note, I cannot state enough how large of a role Dan Kahan played in getting my mind turning on this subject. I have shared Karl Popper’s views on the scientific enterprise for some time, but Dan Kahan helped me start connecting my understanding of the philosophy of science to modern day issues in science. His blog can be found here.