Jerry Coyne on reductionism

Leiter and Weisberg: Nagel opposes two main components of the “materialist” view inspired by Darwin’s theory of evolution by natural selection. The first is what we will call theoretical reductionism, the view that there is an order of priority among the sciences, with all theories ultimately derivable from physics and all phenomena ultimately explicable in physical terms. We believe, along with most philosophers, that Nagel is right to reject theoretical reductionism, because the sciences have not progressed in a way consistent with it. We have not witnessed the reduction of psychology to biology, biology to chemistry, and chemistry to physics, but rather the proliferation of fields like neuroscience and evolutionary biology that explain psychological and biological phenomena in terms unrecognizable by physics. As the philosopher of biology Philip Kitcher pointed out some thirty years ago, even classical genetics has not been fully reduced to molecular genetics, and that reduction would have been wholly within one field. We simply do not see any serious attempts to reduce all the “higher” sciences to the laws of physics.


Coyne: Here all three academics (Weisberg is a philosopher; Leiter a professor of law) make a mistake: the view that all sciences are in principle reducible to the laws of physics, which is materialism, is not identical to an attempt to reduce all sciences to physics. The former must be true unless you’re religious, while the latter is a tactical problem that will be solved to some degree as we understand more about physics and biology, but is unlikely in our lifetime to give a complete explanation for higher-level phenomena. Remember, though, that “emergent phenomena” must be consistent with the laws of physics, even those laws may not be useful for explaining things like natural selection.


VR: Thanks, Jerry, for attacking nonreductive materialism, which is the strongest form of materialism.

Clayton and Doctor Logic on Reduction

Clayton: Here's a standard view for materialists to take. Arguments against materialism in mind fail because they fail to take account of non-reductive forms of materialism.

Doctor Logic: I'm gonna say that non-reductionist emergence is, indeed, poofy. It's no better than dualism because it says that mental properties are inexplicable.

But Arrington is attacking a straw man if he's going after the mainstream consensus. The mainstream view is reductionist, not poofy emergentism.

VR: I find problems with non=reductive materialism because it has serious difficulties accounting for mental causation. Also, it posits a supervenience relationship between the physical and mental, but everything is supposed to supervene on the physical, and the supervenience relation, which has to be real, doesn't supervene on the physical. I don't accept the reductivist position because attempted reductions simply slide over the logical distinction between the mental and the physical. All the physical information in the world is insufficient to logically guarantee that a thought is about P and not about Q.