William James is remembered as one of the most important psychologists and philosophers from the turn of the 20th century, and one of his most cherished works is The Varieties of Religious Experience. Originally a set of talks given at the prestigious Gifford Lectures, the book chronicles James’s investigation into the stages religious believers ascend on their path, describing the difference between ‘healthy-minded’ living and ‘sick-soul’ living as well as an early investigation into mysticism.