The dreams indeed are for the most part cut to the same pattern, and very few of them are really of a kind that can be taken seriously ; but of these very few there normally is some one or other that haunts us all our life. One such, to the lure of which the joint authors of the present undertaking fell victims - each independently, and after his own fashion was that of writing a monumental History of Indian Philosophy. We both of us can yet recall - vividly as though it happened just the other day - the occasion when the fascination first caught hold of us. DR. Belvalkar upon whom the idea dawned when he was making his first acquaintance with Sankaracarys's immortal Bhasya on the Brahmasutras placed himself immediately under the direction of the late Dr. F. G. Selby, who, in his days, did so much for the promotion of philosophical studies. Thus to the volume now published Dr. Belvalkar contributed the portions dealing with early Vedic, Brahmanic and post Upanisadic speculations, Upanisadic stratification, and the general evaluation of Upanisadic philosophy, while Professor Ranade contributed the critical expositions of most of the individual Upanisadic texts. Of course, before these contributions took their final shape, they were discussed by the authors together and thoroughly revised, so that ultimately the authors hold themselves jointly responsible for everything that is written in the book.