Saint Augustine of Hippo, Saint Augustine, Thomas A'Kempis (2006). “The Confessions of St. Augustine, Including the Imitation of Christ”, p.56, Cosimo, Inc.
John Calvin (2002). “The Bondage and Liberation of the Will (Texts and Studies in Reformation and Post-Reformation Thought): A Defence of the Orthodox Doctrine of Human Choice against Pighius”, p.287, Baker Books