My research centres on the history of Modern Europe in the nineteenth and twentieth centuries. I focus expecially on France, writing interdisciplinary cultural history that combines the history of religion and gender, as well as medicine and science. I began by examining the emergence of the 'insanity defence' in Paris when work on unconscious mental activity and criminal anthropology shook the foundations of legal responsibility. I then moved to exploring Catholic revivalism and healing, especially at the shrine at Lourdes. My third work was a study of the Dreyfus Affair which explored what distinguished a cause célèbre from conventional politics, and analysed the politics of commitment. This work was awarded the Wolfson Prize in 2010. My published work on these subjects include The Man on Devil's Island:Alfred Dreyfus and the Affair that Divided France, (Harmondsworth, 2010), Lourdes: Body and Spirit in the Secular Age (1998) and Murders and Madness: Medicine, Law and Psychiatry (Oxford, 1989).
Since then, I have begun a large project on religious revival which focuses on the links between South Asia and the West. I have published on Gandhi and Romain Rolland; am analysing the the Indian origins of Albert Schweitzer's 'reverence for life,' and am undertaking new work on Anagarika Dharmapala, Vivekananda and their relationship to Western thought.