Robert Pennock Takes the Stand in Dover Trial
Methodological Materialism and What If
The third morning of Kitzmiller vs. Dover found philosopher of science Robert Pennock testifying for the plaintiffs that science is a search for natural explanations of natural phenomena--a limitation known as methodological naturalism (or methodological materialism).
Pennock presented this as the definition of science, and said proponents of intelligent design are “trying to overturn" it, but later he conceded that there was a controversy among philosophers of science concerning whether methodological naturalism was essential to the definition of science.
Earlier in the trial, the ACLU led its first expert witness, biologist Kenneth Miller, through some counterfactual (or “what-if”) reasoning, an investigative tool often used by philosophers. I wish one of the attorneys had led Pennock through the following ‘what if” scenario (in this case, a counterfactual that might be actual): What if something in the natural world was the product of design--say, the origin of the first life, or the fine tuning of the physical constants for life?
Now, a materialist might respond, “Well it wasn’t,” as if the mental exercise is some sort of sneaky, schoolyard trick: “Will you pretend for a minute that I’m cooler than you?” “All right, why?” “Ha! You admit it. I’m cooler than you.”
That’s not the point of this exercise. The purpose is to shed light on methodological materialism. Scientists have thus far failed to uncover a purposeless, material cause either for the fine tuning of the physical constants of nature, or for the simplest self-reproducing cell. Further, both the fine tuning and the simplest cell have the hallmark of designed systems, a truth we know from long and detailed experience with human designs.
Return now to the “what if.” Setting aside for a moment what you believe about the origin of fine tuning and the first cell, temporarily assume they arose from a designing intelligence. Will methodological materialism assist or impede a scientist seeking the truth about their origin? Obviously, methodological materialism would stand like an iron curtain between the scientist and the truth.
Methodological Materialism: Helpful Until it Isn’t
Now, of course, that doesn’t prove these two things were designed. We temporarily assumed this to clarify something else: Methodological materialism doesn’t work if we’re considering something that actually had an intelligent cause; thus, methodological materialism would only be consistently fruitful if nothing in nature were designed.
But surely that's an open question. To insist that methodological materialism is always preferable in scientific investigation merely begs some central questions: Is anything in the natural world the product of intelligent design? And if something was designed, could we tell?
Of course, we know that many things in nature spring from material causes. We will no doubt uncover more. But it doesn’t follow from this that all things in nature originated from material causes. Scientists should be free to follow the evidence to the best explanation.
Counterfactual Reasoning and the Slippery Slope Fallacy
Interestingly, Miller and Pennock each invoked a counterfactual in their defense of methodological materialism, so in the interest of aesthetic balance, let’s consider their argument. They said an omnipotent designer could have made the universe a few minutes ago and given us all false memories to make us think it was old. Thus, someone could entertain any sort of design scenario for anything and everything. But where would science be if everybody thought that way. The solution they offered? Methodological naturalism.
But this is the slippery slope fallacy: If we let a designing foot in the door, then before you know it our brains will turn to jelly and we’ll be invoking design at the least drop of a hat.
The best cure for one form of irrationality isn’t to flee into the opposite irrationality. The founders of modern science--e.g., Copernicus, Kepler, Newton--were open to evidence of design, and clearly their brains didn’t turn to jelly. Between the unreasonable extremes of hyper-skeptical illusionism on the one hand and unbending methodological materialism on the other lies the path of reason. One can remain open to the possibility of design and go right on being rational and measured, go right on looking hard for new and more elegant regularities in nature that were previously a mystery. In some cases, the researcher will do both at one and the same time, as when astrobiologist Guillermo Gonzalez and philosopher Jay Richards elucidated a cosmic correlation between habitability and discoverability, and from this inferred intelligent design.
Science teachers should be free to discuss with curious students contemporary design arguments. The ACLU disagrees, exhibiting a feverish interest in banning the mere mention of such ideas in the science classrooms of our public schools.