Synopsis The systems of Indian philosophy represent the attempts at a logical explanation of the problem of a reality and a reasoned interpretation of spiritual experiences. Traditionally, the systems are divided into the ‘Astika darsanas’, i.e. the orthodox systems and the ‘Nastika darsanas’, i.e. the heterodox systems – Buddhism and Jainism. The division is founded on the acceptance or rejection of the Vedas as the source of authority, not only in the worldly but also in the spiritual matters (srutipramanya). The six orthodox systems of Indian philosophy profess a allegiance in varying degrees to the authority of the Vedas and thus display a profound regard for tradition, a positive outlook towards the world, the life and its manifold activities, these are some of the features shared in common by these systems which mark then out from Buddhism. Buddhism signified right from its origin a negative attitude in different field. In the beginning it stood against the sacrificial and ritualistic practices highly prevalent in the society at large, against the distinction among men based on four social classes. In philosophy, as presented by the Brahmanical systems there was first the denial of soul, as supported by the theory of universal flux which meant denial of any enduring thing. Buddhism denied causation as a real process. The six orthodox systems of Indian philosophy have waged a fierce and continuous intellectual warfare with the Buddhist. The present book contains 19 chapters.