not give an exhaustive survey of all the different systems of philosophy. In the present series the author traced, in a historical and critical manner, the development of Indian thought in its different branches from various sources, a considerable portion of which lies in unpublished manuscripts. He spared no pains and underwent a tremendous amount of drudgery in order to unearth the sacred, buried treasures of Indian thought. He revised his original plan of writing only one volume and thought of completing the task in five consecutive volumes constituting a series. He shouldered this gigantic task all alone, with the sincerest devotion and unparalleled enthusiasm and zeal. In 1942 he retired from Sanskrit College and was appointed King George V Professor of Mental and Moral Science in the University of Calcutta. He worked there for three years and delivered the Stephanos Nirmalendu lectures on the history of religions. He had been suffering from heart trouble since 1940, but was still carrying on his various activities and research work. In 1945 he retired from the Calcutta University and was offered the Professorship of Sanskrit at Edinburgh which had fallen vacant after the death of Professor Keith. The doctors also advised a trip to England. On his arrival in England he fell ill again. In November 1945 he delivered his last public lecture on Hinduism in Trinity College, Cambridge. Since then he was confined to bed with acute heart trouble. In spite of his ill health while in England, he was in constant touch with his close students. He stayed in England for five years (1945–50). Even then he published the fourth volume of his History of Indian Philosophy at the Cambridge University Press, the History of Sanskrit Literature at Calcutta University, Rabindranath the Poet and Philosopher with his Calcutta publishers, and a book on aesthetics in Bengali. In 1950 he returned to Lucknow. In 1951, through friendly help given by Pandit Jawaharlal Nehru, he started writing the fifth and final volume of the History of Indian Philosophy. He had also planned to write out his own system of philosophy in two volumes. His friends and students requested him several times to complete the writing of his own first. Yet he looked upon his work on Indian philosophy as the sacred mission of his life, and thought himself to be committed to that purpose. With strong determination and unwavering devotion he brought