theodicy n 1: the branch of theology that defends God's goodness and justice in the face of the existence of evil
Theodicy \The*od"i*cy\, n. [NL. theodicaea, fr. Gr. ? God + ? right, justice: cf. F. th['e]odic['e]e.] 1. A vindication of the justice of God in ordaining or permitting natural and moral evil. [1913 Webster] 2. That department of philosophy which treats of the being, perfections, and government of God, and the immortality of the soul. --Krauth-Fleming. [1913 Webster]