AVATĀRA. The idea of an avatāra, a form taken by a deity, is central in Hindu mythology, religion, and philosophy. Literally the term means "a descent" and suggests the idea of a deity coming down from heaven to earth. The literal meaning also implies a certain diminution of the deity when he or she assumes the form of an avatāra. Avatāras usually are understood to be only partial manifestations of the deity who assumes them.

The avatāra idea in Hinduism is associated primarily with the god Viṣṇu. One of the earliest references to the idea is found in the Bhagavadgītā (c. 200 BCE), where we find a concise statement concerning Viṣṇu's primary intention in assuming different forms:

Whenever righteousness wanes and unrighteousness increases I send myself forth.
In order to protect the good and punish the...