 The year 1641 was an eventful one for Arnauld. He was ordained a priest on September 21. During the year, he completed the “Fourth Objections” to Descartes’ Meditations and wrote De la Fréquente communion (published in 1643). The first work established his reputation as a philosopher. The second went through many editions and had an effect on Catholic sacramental practice up to the end of the nineteenth century. Jansen’s Augustinus was also published in Paris in 1641, having been published posthumously in the Netherlands a year earlier. It was attacked by the official theologian of Paris, Isaac Habert, who preached a series of sermons against Jansen in the cathedral of Paris during Lent, 1643. Arnauld, who had arrived at an interpretation of Augustine similar to, though not identical with, that of Jansen, undertook, at the request of Saint-Cyran, to defend Jansen against the accusation of heresy. This he did in his Première Apologie pour Jansénius, 1644, and Seconde Apologie, 1645. Although Arnauld did not agree with important details of Jansen’s view, he continued to defend Jansen against the charge of heresy off and on for the rest of his life.