Aim in this work has been to give a clear, comprehensive and critical account of the various systems of Indian philosophy. The book will be found useful by all those who want a clear and accurate exposition of the development of Indian philosophical thought in one volume which is neither too small nor too big. On almost all fundamental points the author has either quoted from the original texts or referred to them to enable the interested reader to compare the interpretations with the texts. Throughout the exposition of the different systems which involves criticism and evaluation, the author has tried to be fair and impartial to them and to present many difficult and obscure points in as clear and correct a manner. Ignorance of Indian philosophy, specially of Buddhism and Vedanta, is still profound and has given rise to un-informed or ill-informed accounts and misleading criticisms. It has been the aim of the book to remove such misconceptions. Honest difference of opinion in interpretation is legitimate in philosophy, but it does not entitle us to impose our own preconceived notions on a system which are repelled by its original texts. The work is only an outline of a vast subject and has no pretensions to completeness. The present treatise is a critical study of different systems of Indian Philosophy based on original sources and its principal value lies in their interpretation. On almost all fundamental points the author has quoted from the original texts to enable the reader to compare the interpretations with the text. The book opens with the survey of Indian philosophical thought as found in the Vedas, the Upanisads and Bhagavadgita. It proceeds to the study of Materialism, Jainism and Early Buddhism, Sunyavada, Vijnanavada and Svatantra Vijnanavada