This study began as a search for a deeper understanding of the nature of vital religious experience. The first inspiration for a method of approach came from Baron von Htigel's classic description of the three elements which constitute religious experience, the mystical-intuitive, historical-institutional, and rational-philosophical. Equipped with this insight, it became apparent that the many hooks which have appeared on the subject of mysticism in the last fifty years have been an attempt to redress the over-balancing emphasis on the institutional in much of twentieth century religion. And since many of then had been inspired by studies of seventeenth and eighteenth century mystical writers, as Ronald Knox's Enthusicsta, for example, it seemed that this might be a fruitful period for investigation. Those who have actually experienced a personal relationship to God are often more helpful tutors than those who describe the experience of others.