For several years before his death Professor William James cherished the purpose of stating his views on certain problems of metaphysics in a book addressed particularly to readers of philosophy. He began the actual writing of this 'introductory text-book for students in metaphysics,' as he once called it, in March, 1909, and to complete it was at last his dearest ambition. But illness, and other demands on his diminished strength, continued to interfere, and what is now published is all that he had succeeded in writing when he died in August, 1910.