De libero arbitrio (Augustine)

De libero arbitrio (libri tres) (English: On Free Choice of the Will) is a book by Augustine of Hippo about the freedom of will. Young Augustine wrote it in three volumes, one 387–389 in Rome, after his baptism, and the other two between 391 and 395, after his priestly ordination in Africa.

The author started De libero arbitrio as a part of a series of works against Manichaeism and argued in favor of aspects of Scepticism. Augustine challenged Determinism in the first volume and investigated the conditions of the existence of God and knowledge in the other two parts.