Augustinianism is the philosophical and theological system of Augustine of Hippo and its subsequent development by other thinkers, notably Boethius, Anselm of Canterbury and Bonaventure.[1][2][3] Among Augustine's most important works are The City of God, De doctrina Christiana, and Confessions.

Originally, Augustinianism developed in opposition to Pelagianism;[4] it was widespread in medieval western philosophy until the arrival of Thomism and Aristotelianism.[5]

Plato and Plotinus influenced Augustine in many ways, and he is considered a Neoplatonic philosopher.[6][7][8] The Augustinian theodicy and other Augustinian doctrines such as the divine illumination and the invisible church show a strong Platonic influence.[9][10][11]

Pope Benedict XVI cautioned that all of the Western Church teaching leads to him:

St Augustine. This man of passion and faith, of the highest intelligence and tireless in his pastoral care, a great Saint and Doctor of the Church is often known, at least by hearsay, even by those who ignore Christianity or who are not familiar with it, because he left a very deep mark on the cultural life of the West and on the whole world. Because of his special importance St Augustine's influence was widespread. It could be said on the one hand that all the roads of Latin Christian literature led to Hippo (today Annaba, on the coast of Algeria), the place where he was Bishop from 395 to his death in 430, and, on the other, that from this city of Roman Africa, many other roads of later Christianity and of Western culture itself branched out.[12]