Avatāra

Lesson 23 described Viṣṇu as the deity who keeps things going. This lesson takes up the mechanism by which he does it.

Avatāra comes from ava-√tṝ, to cross down, and the lexicon's first gloss is exactly that: descent, especially of a deity from heaven, the appearance of a deity upon earth.

The usual English rendering, "incarnation", imports a good deal the Sanskrit does not carry. In Christian usage incarnation names a unique event in which God takes on flesh permanently and fully. Avatāra names something repeatable, plural, and — in most Hindu theologies — not a diminishment: the descending Lord does not cease to be what he is, and does not become the form in the way a person becomes an adult.