A centenary is often an excuse for reminding people of the life and work of a predecessor, especially if the material is of contemporary relevance. Published 100 years ago, William James' The Varieties of Religious Experience, remains the most revealing investigation into the psychology of religion. James, a nonpracticing MD, turned his thoughts to psychology and philosophy. The book was considered “one of the great books of our time” and in it, James bravely tackled a subject that many then, and perhaps now, considered taboo.

James' aim was to study religious experiences as he would any other psychological phenomena, accepting their reality and vulnerability to scientific enquiry. His definition of religion was “the feelings, acts, and experiences of individual men in their solitude, so far as they apprehend themselves to stand in relation to whatever they may consider the divine.” He was concerned with immediate personal experiences, which he considered to be universal to humanity.

In his lecture, “Religion and Neurology,” he explored the potential psychophysical associations of religious feelings. In order to understand the nature of religious experience, James emphasized the need to study those for whom religion was “an acute fever,” and not to dwell long on those whose commerce with the deity was “second hand.” The ones to study were the “geniuses of the religious line.” However, he warned that they “like many other geniuses that have brought forth fruits effective enough for commemoration in the pages of biography, have often shown symptoms of nervous instability.” He pointed out that “insane conditions” have a considerable advantage for studies of this kind because they isolate specific factors of the mental life that become available for investigation.