Body and Will was the title of a book by the psychiatrist Henry Maudsley, published in 1883. Speaking of the will, he said: ‘To have any understanding in the matter we must substitute for the metaphysical notion of a mental entity the physiological conception of a confederation of nerve-centres’. Maudsley claimed new physiological knowledge was over-running the citadel of pretentious claims to ‘high mental philosophy’.

This chapter examines Maudsley's claim and others like it, insofar as they appeared to question the freedom of the will, in Maudsley's terms to substitute knowledge of ‘nerve-centres’ for a ‘metaphysical notion’. I outline the physiological background of the claims before engaging the debate in the 1870s centred on the perceived automatism of human activity. This debate drew in philosophical argument, medical interests and public fascination with madness, unconscious mental life, spiritualism, degeneration and a good deal else besides. The richness and complexity of William James's response demands a separate section.

The fact is, however much doctors and scientific naturalists argued for regularity of cause and effect, they did not let go of the will. They called on people to understand and to follow Nature. Linking mind to the physiology of the nervous system they sought a new basis for action.