The Need for Naturalism in a Scientific Age

May 18, 2010

It’s only natural to wonder if any philosophy is really needed anymore, in this age of science. Isn’t the point of science to replace sheer speculation and metaphysics?

One philosophy is compatible with science, because it is the worldview that results when people take science seriously. That philosophy is naturalism. Still, people may wonder why any "ism" is still needed when we have all the knowledge that the sciences provide. What sort of knowledge, over and above science, could be possible or useful? Religion tries to supplement science, so when science replaces religion, doesn’t that mean that all philosophy is committed to the flames as well?

Let’s first be clear about what naturalism basically is.

Naturalism is a worldview, a philosophy – a general understanding of reality and humanity’s place within reality. Naturalism can be briefly defined as the philosophical conclusion that the only reality is what is discovered by our intelligence using the tools of observation, reason, and science.

As a philosophy, naturalism is far more than just empirical science, but it does depend on science. Naturalism is useful precisely because no particular science could have the task of experimentally confirming that the only reality is what is discovered by our intelligence. Science points towards, but does not verify, such a general conclusion. Naturalism is also useful because no particular science could have the task of empirically confirming the validity of scientific methodology. Looking outwards from the conclusions of science, and looking inwards into science’s workings, is philosophical work. It is also necessary work.

What exactly has naturalism been doing?

Naturalism emphasizes the progressive and expanding knowledge that observation and science provides. Science continually revises its understanding of natural reality. Naturalists from the ancient Greeks to modern times have tried to keep up with the science of its age. Today’s scientists have new conceptions of energy and matter that most 19th century scientists would have found incomprehensible. 21st century scientists will likely demand major revisions to today’s best theorizing about what nature. Because science’s best ideas about nature undergo improvement, naturalism is a philosophy that requires intellectual humility: while nature is discoverable by science, naturalism cannot offer any final and perfect picture of exactly what this reality is like. Therefore, the primary task of philosophical naturalism is not to defend science’s current best theories about reality – science itself is responsible for reasonably justifying its own hypotheses. Philosophical naturalism undertakes the responsibility for elaborating a comprehensive and coherent worldview based on experience, reason, and science, and for defending science’s exclusive right to explore and theorize about all of reality, without any interference from tradition, superstition, mysticism, religious dogmatism, or priestly authority.

Science therefore has four close relationships with naturalistic philosophy.

First, when the various sciences question their ultimate principles and ponder how these principles can reasonably cohere together, science becomes philosophy and intellectuals undertaking these problems are both philosophers and scientists. For example, leaders of scientific revolutions, from Aristotle, Galileo, and Newton to Helmholtz, Mach, and Einstein, are justly recognized for their major philosophical contributions. Naturalism is the effort to make sure that the separate social and physical sciences remain coherent and consistent with each other. Ensuring that all the sciences are describing the same reality cannot be task of any particular scientific discipline.

Second, when the logical reasoning of scientific method requires scrutiny so that it can be better understood or improved, naturalistic philosophers explain and justify scientific method without resorting to any unnatural principles. The investigations and improvements upon logical methods of inference, the very engine of scientific methodology which justifies science’s conclusions, is philosophical logic—the normative inquiry into rational inquiry. Furthermore, theology want to credit a god for our powers of reason, but naturalism makes sure that we can explain human intelligence only in terms of our own brain functioning.

Third, when the sciences are under intellectual attack by jealous rivals offering supernatural hypotheses or paranormal modes of knowledge, science turns to naturalistic philosophy for explanations why these unscientific alternatives are irrational and unnecessary. Skepticism is grounded on naturalism. Naturalism is the best rival to religion , since no particular scientific field could have the task of empirically refuting sweeping metaphysical or theological claims. Specifically, philosophical naturalism supplies the philosophical atheology to counter the arguments over the existence of god against philosophical theology. Furthermore, naturalism can explain the origins of religion itself .

Fourth, when the sciences are under political attack by hostile forces wanting to obstruct scientific research or inhibit scientific teaching, science turns to naturalistic philosophy for staunch defenses of ethical humanism, intellectual freedom, and democratic secularism. Naturalism is the best philosophical foundation for explaining why people can be good without god , why we don’t need spooky free will, why the humanistic defense of human rights is so crucial , why democracy can work without divine or priestly decrees, why religions cannot be trusted with political power, and why the separation of church and state is necessary for human welfare.

In summary, science occasionally rises to the level of naturalistic philosophy; naturalistic philosophy explains, justifies, and improves scientific method; naturalistic philosophy defends science and reason against supernaturalism and irrationalism; and naturalistic philosophy supports a liberal political order capable of protecting science.

All four essential tasks of philosophical naturalism cannot be done by any of the sciences themselves. That’s a good thing, because we want the sciences to stay closely focused on their own task: discovering how the world actually works.