Friday, July 17, 2009

Discovery, Demonstration, and Naturalism

Over the past several months or so, I've approached discussions of science by focusing on the concept of discovery. Science is the formalization of discovery. There are as many scientific methods as there are formal methods for discovering phenomena. Accidental discoveries can be utilized by science, in so far as they can lead to formal methods of discovery.

It occurs to me that this view of science, while essentially valid, might be easier to communicate if I adopt another term: demonstration. Science deals in what is demonstrable. A method of discovery is a set of rules or procedures for demonstrating facts. A scientific method is defined by its rules and procedures for demonstrating facts about the world.

We might ask, what is being discovered here? Is it the rules, or is it the facts?

The answer is: both. A scientific discovery is defined in terms of the facts discovered as well as the rules/procedures for demonstrating those facts. It is the relationship between rules and facts which defines a scientific theory as such.

This leaves the question: What is the purview of scientific discovery? Are there some things which cannot be discovered/demonstrated, but which act as guiding forces in our lives?

Sean Carroll approaches this question in a recent contribution to Discover Magazine entitiled "What Questions Can Science Answer?" Carroll does a decent job of describing the way science approaches questions of fact. He also points out the need to clearly define our terms. Yet, while he says the term "science" is well enough understood, he offers a problematic definition of "natural."

In what is essentially a definition of "naturalism," he writes: "By 'natural' I simply mean the view in which everything that happens can be explained in terms of a physical world obeying unambiguous rules, never disturbed by whimsical supernatural interventions from outside nature itself."

Scientists do not rely on any notion of the supernatural to formulate their conception of nature. So why include the word "supernatural" in the definition of "natural?"

Also, it is not clear that the world "obeys unambiguous rules." It is not even clear what that means. Perhaps Carroll means the world acts in a manner consistent with the predictions made by unambiguous rules. If we remove the part about the supernatural and clarify the reference to rules, we end up defining "nature" as that which can be methodically demonstrated. Nature is what is open to formal discovery, by definition.

Naturalism is not a scientific hypothesis which might eventually be falsified. It is not a conclusion based on scientific evidence. Naturalism is true by definition. It is a framework for talking about discovery and demonstration. It is a language for understanding the relationship between knowledge and action. The words "nature" and "science" go together like "bachelor" and "unmarried."

This makes it easier to correct a misconception regarding quantum mechanics. In quantum mechanics, there are events or relationships which are somewhat unpredictable, or "whimsical." This is not to say they suggest a "supernatural" or any other kind of intervention, though. The notion of intervention implies directedness, and there is no evidence that quantum unpredictability is somehow directed towards any ends. The whole point is that it lacks direction.

Quantum unpredictability does not undermine a naturalistic view of the world. It does not undermine the meaning or value of science. In fact, quantum unpredictability is quantified scientifically. Scientific theory predicts a certain degree of unpredictability, and measurements of that unpredictability can be tested against scientific theory. The so-called "whimsical" aspects of quantum mechanics might defy common sense, but they do not defy scientific practice.

The point to stress here is that, if there were some intent or direction behind these events, some force which guided the course of nature, it would be scientifically discoverable. It would be worthy of the term "nature."

Carroll's argument misses this important point. He takes the terms "natural" and "supernatural" to indicate equally coherent, competing theories of the world. He says: "The preference for a natural explanation is not an a priori assumption made by science; it’s a conclusion of the scientific method. We know enough about the workings of the world to compare two competing big-picture theoretical frameworks: a purely naturalistic one, versus one that incorporates some sort of supernatural component."

Carroll's view is wrong, and in a dangerous way.

The term "naturalism" has no place in science. It is a political rejoinder against supernaturalists, and nothing more. Supernaturalists wish to protect their beliefs and institutions from scientific scrutiny, simultaneously promoting the contradictory claims that they are beyond science's purview and that science must change to allow for their beliefs. Yet, the term "supernatural" remains incoherent.

Supernaturalism is not a philosophical or scientific point of view. It is a political strategy to corrupt our understanding of the relationship between knowledge and action, and our understanding of science and nature should not be compromised by it. When Carroll says naturalism offers "a more compelling fit to the observations," he is playing into a political trap. He is opening the door to a debate about how well naturalism is supported by the evidence; as though naturalism were defined in testable terms. At best, this will lead to confusion. At worst, it will fan the flames of ignorance about the value and meaning of science.