Is Biology Reducible to the Laws of Physics?

John Dupré reviews Darwinian Reductionism: Or, How to Stop Worrying and Love Molecular Biology by Alex Rosenberg, in American Scientist:

Alex Rosenberg is unusual among philosophers of biology in adhering to the view that everything occurs in accordance with universal laws, and that adequate explanations must appeal to the laws that brought about the thing explained. He also believes that everything is ultimately determined by what happens at the physical level—and that this entails that the mind is "nothing but" the brain. For an adherent of this brand of physicalism, it is fairly evident that if there are laws at "higher" levels—laws of biology, psychology or social science—they are either deductive consequences of the laws of physics or they are not true. Hence Rosenberg is committed to the classical reductionism that aims to explain phenomena at all levels by appeal to the physical.

It is worth mentioning that, as Rosenberg explains, these views are generally assumed by contemporary philosophers of biology to be discredited. The reductionism that they reject, he says,

holds that there is a full and complete explanation of every biological fact, state, event, process, trend, or generalization, and that this explanation will cite only the interaction of macromolecules to provide this explanation.

Such views have been in decline since the 1970s, when David Hull (The Philosophy of Biological Science [1974]) pointed out that the relationship between genetic and phenotypic facts was, at best, "many/many": Genes had effects on numerous phenotypic features, and phenotypic features were affected by many genes. A number of philosophers have elaborated on such difficulties in subsequent decades.

The question then is whether Rosenberg's latest book, Darwinian Reductionism: Or, How to Stop Worrying and Love Molecular Biology, constitutes a useful attack on a dogmatic orthodoxy or merely represents a failure to understand why the views of an earlier generation of philosophers of science have been abandoned.

More here.

Comments

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Reductionism doesn't require one-to-one relationships.

You can have biology explained by complex many-many relationships among macromolecules. His stance on reductionism seems commonsense to me?

Either you believe that biology is explained by natural law (and as far as we know, all natural law is reductionist to quantum physics or whatever). Either that or you believe in the supernatural. What scientist can professionally believe in the supernatural?

[Deets]

Hyphen,

As soon as you have "many-to-many relationships," you're no longer talking about reductionism. If reductionism is going to be something other than tautological, it has to mean something more than "reducible to all contributory factors." Conventionally it's meaningful to talk of reductionism in a biological context as the ability to understand an organism's deterministic chains, as we would a robot.

Biology is wisely moving away from this notion, although it is all too persistent among gene-centric natural selectionists (Dennett, Dawkins...). Relationships matter: among genes, between genes and organisms, organisms and environments. Since the number of possible relationships is infinite or near-infinite, biological reductionism in practice is an impossibility.

True reductionism implies predictability. Introduce enough variables, and the picture quickly becomes chaotic enough to exceed our ability to make predictions. Scientific method requires isolating variables, and no variable in nature is truly isolated.