Written sometime between 1904 and 1906, during the latter part of his stay in Baroda, The Philosophy of the Upanishads, though left incomplete by the author, represents an early stage of Sri Aurobindo's thinking on the most important scriptures of Vedanta philosophy. In the Preface he comments that not only is the philosophy of the Upanishads at the base of all Indian religion and morals, and of Hindu politics, legislation, and society, but it has also profoundly influenced Western thought in both subtle and evident ways.