In Eastern Orthodox (Palamite) theology, there is a distinction between the essence (ousia) and the energies (energeia) of God. It was formulated by Gregory Palamas (1296–1359) as part of his defense of the Athonite monastic practice of Hesychasm against the charge of heresy brought by the humanist scholar and theologian Barlaam of Calabria.
Eastern Orthodox theologians generally regard this distinction as a real distinction, and not just a conceptual distinction. Historically, Western Christian thought, since the time of the Great Schism, has tended to reject the essence–energies distinction as real in the case of God, characterizing the view as a heretical introduction of an unacceptable division in the Trinity and suggestive of polytheism.
