Edge‘s big question for 2017 is: “What scientific term or concept should be more widely known?” The compilation of answers (205 in all) makes for fascinating reading. For his part, Professor Jerry Coyne has nominated physical determinism as “a concept that everyone should understand and appreciate.” Unfortunately, Coyne’s defense of this concept leaves a lot to be desired. As I’ll argue below, even if you reject interactionist dualism (as most scientists do), you can still believe in libertarian free will.
Professor Coyne begins by mis-defining determinism as the notion that “all matter and energy in the universe, including what’s in our brain, obey the laws of physics.” I know of no philosopher who defines determinism in this way. The Stanford Encyclopedia of Philosophy, for instance, roughly defines causal determinism as “the idea that every event is necessitated by antecedent events and conditions together with the laws of nature.” Coyne says nothing about antecedent conditions, and fails to even mention the notion of necessitation.
To illustrate what’s wrong with Coyne’s definition, I’ll use an analogy which is often cited by philosophers: the game of chess. All the pieces obey the rules (or laws) of the game, but those laws don’t tell the player where to move the pieces. Even if the pieces were capable of moving themselves without the help of an outside agent, nothing in the rules of the game would determine the moves that followed. That’s because the rules of chess merely constrain the set of moves which are allowed, without determining the movement of any of the pieces. What Coyne needs to show is that the laws of physics are more than mere constraints, and that for any given collection of molecules, they narrow down the set of possible outcomes to just one, and no more.