The Dutch Roman Catholic theologian Cornelis Jansen (1585-1638) wrote an interpretation of St. Augustine's teachings on original sin and grace. Although condemned by the Church, his teachings, known as Jansenism, had an enormous impact.

Cornelis Jansen was born near Leerdam, Holland, and he received his early education in Leerdam and Utrecht. In 1602 he went to the Catholic University of Louvain in the Spanish part of the Netherlands (now Belgium). Soon he was introduced to the theology of Michael Baius, a former master of divinity at the same university. Baius's doctrine on grace and original sin had been condemned in 1567, but the battle continued between his Augustinian supporters and the Jesuits (led by Leonard Lessius). The young student's sympathies were all with the Augustinians.

In 1604 Jansen fell ill and went to live in Paris, where he became more and more intimate with a fellow student of his Louvain days...