We are discovering more and more about human genotypes and about the connections between genotype and behaviour. Do these advances in genetic information threaten our free will? This chapter offers a philosopher's perspective on the question.

Whether or not genetic discoveries do really threaten free will, many feel threatened, and it is not difficult to see why. If genetic advances enable us to predict with increasing accuracy and reliability what people will do, this seems to undermine the pretensions of individual autonomy and agency. In what sense do I choose for myself what I do, if you can say reliably in advance what that choice will be?

The free will dilemma is a hardy philosophical perennial. After thousands of years of work there is still no generally accepted solution, no clear demonstration that free will really is possible. A philosopher may well wonder how new genetic knowledge could make things any worse, or indeed make things any different.

The sceptical dilemma and diminished responsibility

To see why a philosopher might suspect that genetic information could not possibly make the problem of free will any worse than it already is, we need to consider the classic free will dilemma, an argument with three very plausible premises and a depressing conclusion. First, everything that happens in the world is either determined or not. Second, if everything is determined, there is no free will.