In Christian theology, the beatific vision is the eternal and direct perception of God enjoyed by those who are in Heaven, imparting supreme happiness or blessedness. While humans' understanding of God while alive is indirect (mediated), the beatific vision is direct (immediate). Thomas Aquinas defined the beatific vision as the ultimate end of human existence after physical death. Aquinas's formulation of beholding God in Heaven parallels Plato's description of one beholding the Good in the world of knowledge.