Kenosis

The word comes from the Greek kenōsis, emptying, and the doctrine is built on Philippians 2:6–7, where Paul describes Christ as having "emptied himself, taking the form of a servant." Exactly what Christ emptied himself of is a matter of intense theological disagreement. Did he give up omniscience? Omnipotence? Only the outward privilege of divinity? Or was the emptying a purely functional self-limitation for the sake of the incarnation?

The doctrine matters because it is one of the main ways Christian theologians try to answer a basic puzzle: how can a being who is, by definition, unchangeable and maximally perfect, become a human child who grew tired, felt pain, and said he didn't know the hour of the last judgment? Orthodox Christianity (and later Roman Catholicism) generally holds that Christ retained every divine attribute but chose not to exercise some of them. Nineteenth-century kenotic theologians pushed further, arguing that certain attributes (omniscience in particular) were genuinely, not just functionally, relinquished.

For non-Christians, kenosis is a useful term because it surfaces a live tension inside Christian theism. The doctrine of divine immutability says God cannot change. The doctrine of the incarnation says God became human and changed quite a lot. Kenosis is one of the moves theologians use to hold both ideas together, and the move has costs — in particular, it makes Christology dependent on a contested reading of a single Pauline hymn.