Divine Simplicity is the most metaphysically rigorous of the classical attributes. It holds that God is not composed of parts — not of body and soul, not of essence and attributes, not of being and act. God's attributes are not separable components of Him; they are Him, considered from different angles. "God is love" (1 John 4:8) does not mean love is a thing God has; it means God is identical with love. The same is true of wisdom, power, holiness, justice, and goodness. This sounds abstract, but it has enormous consequences. Divine Simplicity rules out: (1) any possibility that God's love might conflict with His justice (they are the same thing, considered differently); (2) any possibility that God has unactualized potential (He is pure act); (3) any possibility that God changes by gaining or losing an attribute; (4) any multiplicity in God's essence that would compromise His oneness. Divine Simplicity has been taught from the earliest fathers through Augustine, Anselm, Thomas Aquinas, the Reformed orthodox, and most of church history until modern times, when various philosophers began to challenge it. It is a deep and mysterious doctrine — indeed, it is the classical church's way of saying "God's being is as incomprehensible as it is real." He is not the biggest thing in the universe; He is the ground of all being, infinitely beyond our categories.