(Sanskrit: “identity and difference”), an important branch of Vedānta, an orthodox system of Hindu philosophy. Its principal author was Bhāskara, probably a younger contemporary of the great thinker Śaṅkara of the Advaita (Nondualist) school. The mainstay of Bhāskara's philosophy was the conviction that acts and knowledge are not mutually exclusive but, rather, mutually reinforcing. In contrast, Śaṅkara held that ultimately only total resignation and withdrawal from acts are necessary to attain release. Against this view, Bhāskara upheld the doctrine of the “cumulative effect of acts and knowledge” (jñāna-karma-samuccaya) and declared that a person should only withdraw after an active life in which he fulfilled his obligations. On the important issue of the relationship between brahma (the absolute) and the world, Bhāskara taught that the two are identical; if, he said, brahma is the substantial cause of the world, then the world itself is real. Difference occurs when certain limiting conditions (upādhis) are imposed on brahma.

Bhāskara's doctrine never became widely accepted, for Śaṅkara had already expounded his own view, which soon gained great influence. Nevertheless his work remains important, for it documents the typical Brahman (priestly class) concern with the implementation of the dharma—that is, those caste and individual obligations that keep the world in balance and produce the good society. In Bhāskara's opinion, the tenet that the world is, in the end, illusory attacks the validity of this dharma, and the commandment of renunciation of the world prevents the fulfillment of it.