But understanding and explaining motives does not compromise freedom; nor does even predicting acts necessarily do so. A person committed to a political cause may vote predictably, and intelligibly in an election. He does not vote less freely than someone that flips a coin at the last minute. So if we find comparison with animals any help in understanding motives, it will not mean that conduct is not free. And since animals are not (as Descartes supposed) automata, the issue of freedom does not make comparing man with any other species and downgrading irrelevance.
Introduction, Beast and Man: The Roots of Human Nature (1979).