This book argues that the origins of Indian philosophy should not be traced to the Vedic Upanisads. Instead, various non-Brahmanical movements developed philosophical ideas that later influenced Brahmanism. The different strands of thought that contributed to this historical evolution-where non-Vedic elements played a predominant role-are identified and analyzed in detail. The book concludes by examining the Vedic response to these developments, which gradually gained prominence over time.