The past week here at ENV we’ve been celebrating the 20th anniversary of the publication of Phil Johnson’s Darwin on Trial. An angle on the subject as yet unexplored is Johnson’s chapter on “The Rules of Science” and how it relates to neuroscience and to ethics.
That important chapter discusses certain assumptions underlying the scientific endeavor. With reference to Kuhn’s Structure of Scientific Revolutions, Johnson takes a step back from the details of his case study and the associated empirical evidence to look at the philosophical underpinnings of the scientific process as a whole. He identifies the prevailing paradigm in science as a commitment to naturalism.
Part of Johnson’s argument is that this commitment informs the interpretation of observed data as well as the recognized limits to possible explanations. This limitation can pose problems when phenomena do not fit within the explanatory guidelines. Which brings us to neuroscience. If naturalistic explanations are the only allowed explanations, then emotions, the mind (as opposed to the brain), decisions, and the will must all be engendered by physical processes emerging from the neural networking of the brain.
The widespread commitment to naturalism and to its philosophical cousin, materialism, has spurred debate about free will versus determinism. A recent Nature News article included an interesting discussion of the differing views among neuroscientists and philosophers. If our free will is only apparent, then in reality our actions are all determined. However if free will is real, then according to the prevailing paradigm, it needs to be explained as a product of physical forces. This question is important enough that the Templeton Foundation recently announced a $4.4 million grant for a four-year project on free will.
This is an area where our interpretation of the data (or the lack of data) has direct consequences for ethics. Neuroscientist Patricia Churchland researches the relationship between biology and ethics, on which she takes a naturalistic view. She commented in the Chronicle of Higher Education:”I would read contemporary ethicists and just feel very unsatisfied. It was like I couldn’t see how to tether any of it to the hard and fast. I couldn’t see how it had anything to do with evolutionary biology, which it has to do, and I couldn’t see how to attach it to the brain.”
Churchland has studied the relationship between the brain’s chemical activity and morality. She works on the assumption that ethics must be connected to evolutionary biology, and accordingly seeks naturalistic explanations of ethics. Well, given what she assumes, searching for a chemical or physical cause for ethical choices only makes sense.
For example, Churchland cites Prairie Voles to illustrate how chemical processes inform morality. Prairie Voles with a greater number of oxytocin receptors were monogamous while those with fewer receptors were not. Churcland therefore concludes that the decision to be monogamous, whether on the part of this mouse-like creature or a human being, must have a biological basis.
Inevitably this calls into question the basis for morality. Churchland takes a pragmatic view:“Where we get a lot of pushback from philosophers is that they’ll say, ‘If you go this naturalistic route that Flanagan and Churchland go, then you make ethics merely a theory of prudence.’ And the answer is, Yeah, you kind of do that. Morality doesn’t become any different than deciding what kind of bridge to build across a river. The reason we both think it makes sense is that the other stories” — that morality comes from God, or from philosophical intuition — “are just so implausible.” However, the free will/determinism question and the mind/brain question are still debatable, which is why there remains research interest in the field. Scholars wrestle with the great mysteries: Is the mind an emergent property of the physical brain or is it separate from but related to the brain? Within a naturalistic framework, the mind must be a product of the brain. However, under a non-naturalistic paradigm, the mind may be something distinct from the brain. Unfortunately, as long as the naturalistic view holds sway, non-physical or non-natural explanations of certain phenomenon must remain off limits.
Yet that is different from showing a particular explanation to be incorrect or incoherent. Non-natural explanations are not deemed valid objects of scientific investigation in the first place. It may very well be that free will is an illusion, or that “the mind” is really a product of the physical functions of the brain, but it is important to recognize that within a naturalistic paradigm this question is not really even permitted to be asked.
But as Dr. Michael Gazzaniga implies in an interview with Scientific American, anything other than a naturalistic explanation is primitive:

As I see it, this is the way to think about it: If you were a Martian landing on Earth today and were gathering information about how humans work, the idea of free will as commonly understood in folk psychology would not come up. The Martian would learn humans had learned about physics and chemistry and causation in the standard sense. They would be astonished to see the amount of information that has accumulated about how cells work, how brains work and would conclude, “OK, they are getting it. Just like cells are complex wonderful machines, so are brains. They work in cool ways even though there is this strong tug on them to think there is some little guy in their head calling the shots. There is not.”

The idea that all phenomena must be explained within a naturalistic framework, and that other paradigms are unenlightened and unworthy of consideration — these are assumptions, not readily shown to be based on empirical evidence. They are the foundational axioms of a particular paradigm. This paradigm may not adequately explain all observations, but for those who have committed themselves to it, observations must be made to fit.
Phillip Johnson patiently takes the reader through the reasoning of Kuhn’s views of scientific paradigms and delineates the priorities behind the naturalistic paradigm that is so prevalent in science today. However, as Kuhn points out, anomalies will mount and eventually the anomalies will need to be addressed, perhaps by our considering a different paradigm.