My former colleague Ryan T. Anderson has a review in this week’s Weekly Standard questioning the claims of neuroscientist Michael S. Gazzaniga’s book Human: The Science Behind What Makes Us Unique . Here’s a sample:
Gazzaniga’s thoroughgoing physicalism, which motivates his reduction of human activities to the domain of the natural sciences alone, is unwarranted. To refute the opposing view that the human person has an immaterial aspect, he gives an evolutionary explanation for it, noting that children are “natural believers in essentialism.” And that, presumably, is enough. If children believe something, it and all related beliefs must be evolutionarily determined and, therefore, false. We think this way only because “our brain processes have been selected over time.”But if Gazzaniga is correct about this, then his arguments are ultimately self-defeating. For if the brain’s output is determined by blind evolutionary forces and has no necessary connection to objective truth, then his neuroscience is also unreliable. How does he know that the methods his brain leads him to use produce results that are true, and not just selected for reproductive success? And, for that matter, how can I assent to Gazzaniga’s conclusions? If my brain happens to organize the “chaos of input” (Gazzaniga’s term) differently from his, on what basis do we settle the dispute?
In fact, if our personhood can ultimately be explained by recourse to brain states, molecules, and smaller physical parts, then what freedom is left for an “I” to engage in the weighing and sifting of argument and counter- argument that makes up academic (including scientific) discourse? In explaining the science behind what makes us unique, Gazzaniga has explained away the “us.” His evolutionary explanations undercut not only religion and traditional morality, but all rationality and free choice, including scientific theories and the very enterprise of conducting research to develop them.
The job for future neuroscientists is to affirm, with Gazzaniga, that the human person stands in continuity with other animals, in many respects. But also in radical discontinuity when it comes to mental life. If traditional philosophical arguments for the immateriality of the intellect are correct, then neuroscientists will need to wrestle with the possibility that our mental life is essentially immaterial, though thoroughly integrated with bodily organs like the brain.
