January 15, 2012


Jerry Coyne on free will (Massimo Pigliucci, 1/14/12, Rationally Speaking)

Jerry's aim is made clear by the following sentence: "The debate about free will, long the purview of philosophers alone, has been given new life by scientists, especially neuroscientists studying how the brain works. And what they're finding supports the idea that free will is a complete illusion." I think that Jerry is wrong on two counts here: first, neurobiology simply cannot settle the question of free will, no matter what the data; second, Jerry focuses on a very small subset of the pertinent neurobiological literature, interpreting it incorrectly.

Before we continue, however, let's hear Jerry's definition of free will: "I mean it [free will] simply as the way most people think of it: When faced with two or more alternatives, it's your ability to freely and consciously choose one, either on the spot or after some deliberation." He continues: "A practical test of free will would be this: If you were put in the same position twice -- if the tape of your life could be rewound to the exact moment when you made a decision, with every circumstance leading up to that moment the same and all the molecules in the universe aligned in the same way -- you could have chosen differently."

As Jerry knows, and immediately admits in the paragraph following this quote, such a test is anything but practical. In fact, it cannot be carried out, ever. Which is why I contend that Jerry and others who push the idea that free will (and consciousness, and moral responsibility) is "an illusion" are mistaken when they think they are doing so on the basis of science. Science, if nothing else, is about empirically testable hypotheses, to which the above scenario certainly does not belong. Rather, Jerry et al. are making a metaphysical argument, an approach with which I'm fine, to a point, as a philosopher, but that is strange coming from people who clearly despise the very idea of metaphysics and scorn anything that cannot be approached by the empirical methods of science.

Knowing that his "practical test" is impossible to carry out, Jerry resorts to two lines of evidence he thinks clinch the case against free will. The first begins with the truism that we are biological organisms made of physical stuff, so that we have to abide by the laws of physics. And these laws, according to Jerry, do not leave room for free will. Of course this conclusion depends on one's concept of free will, and there are several on offer (more on this below). It also depends on entirely unargued for assumptions, including the following: causal closure (i.e., that the currently known laws of physics encompass the totality of causal relationships in the universe); a working concept of causality (one of the most thorny philosophical concepts ever); physical determinism (which appears to be contradicted by physics itself, particularly quantum mechanics); and the non-existence of true emergent properties (i.e., of emergent behavior that actually is qualitatively novel, and doesn't simply appear to be so because of our epistemic limitations). I have opinions about all four of these points, but I don't have a knockdown argument concerning any of them. The point is, neither does Jerry.
Even better, physics demonstrates that we create the "laws" of physics.

Enhanced by Zemanta

Posted by at January 15, 2012 8:56 AM

blog comments powered by Disqus