The road by which William James arrived at his position of leadership among American philosophers was, during his childhood, youth and early maturity, quite as circuitous and unpredictable as were his father's ideas on the training of his children. That Swedenborgian theologian foresaw neither the career of novelist for his son Henry, nor that of pragmatist philosopher for the older William. The father's migrations between New York, Europe and Newport meant that William's education had variety if it did not have fixed direction. From 13 to 18 he studied in Europe and returned to Newport, Rhode Island, to study painting under the guidance of John La Farge. After a year, he gave up art for science and entered Harvard University, where his most influential teachers were Louis Agassiz and Charles W. Eliot. In 1863, William James began the study of medicine, and in 1865 he joined an expedition to the Amazon. Before long, he wrote: "If there is anything I hate, it is collecting." His studies constantly interrupted by ill health, James returned to Germany and began hearing lectures and reading voluminously in philosophy. He won his medical degree at Harvard in 1870. For four years he was an invalid in Cambridge, but finally, in 1873, he passed his gravest physical and spiritual crises and began the career by which he was to influence so profoundly generations of American students. From 1880 to 1907 he was successively assistant professor of philosophy, professor of psychology and professor of philosophy at Harvard. In 1890, the publication of his Principles of Psychology brought him the acknowledged leadership in the field of functional psychology. The selection of William James to deliver the Gifford lectures in Edinburgh was at once a tribute to him and a reward for the university that sponsored the undertaking. These lectures, collected in this volume, have since become famous as the standard scientific work on the psychology of the religious impulse. Death ended his career on August 27th, 1910.