Indian philosophical theories, from their earliest speculative cosmologies and explorations of the nature of human existence—in the Vedas and Upanisads, whose compositions were completed by roughly the first half of the first millennium BCE—emphasized the plight of humans and their struggle towards a soteriological goal. An understanding of the evolution of the world and the place of human beings within it held out the hope of improving their lot, either in some other place after death or in the next life in the round of deaths and rebirths. Or even, as the Upanisads suggested, in the ultimate avoidance of rebirth itself—a theme adopted by much Indian philosophy thereafter.

As in Western metaphysical speculations about the nature of the cosmos and man's place within it, the Indian thinkers made central and vital use of the concept of a cause—karana...