Born in the Champagne region, Bérulle was one of the leading religious figures in early seventeenth-century France. He is known primarily for his mysticism and his intolerance of Protestants. Ordained in 1599, Bérulle founded (1611) the Society of the Oratory of Jesus, also referred to as the Congregation of the French Oratory, a congregation of priests (known as Oratorians) dedicated to the reformation of the clergy. The society quickly flourished, and within a few decades was running dozens of colleges and seminaries throughout France. While Bérulle spoke approvingly of Descartes’ philosophy, his own interests were in theology – where he was heavily influenced by the Neoplatonism of both pseudo-Dionysius and Augustine – and politics. His most popular work was Discours de l’état et des grandeurs de Jésus (1623). Bérulle was made a cardinal by Pope Urban VIII in 1627.

As for his links to Descartes and Cartesianism, Bérulle's Augustinianism was transmitted both directly, through personal relations he had with men who would later have connections of their own with Descartes, such as Charles de Condren and Guillaume Gibieuf, and indirectly, via the Oratorian seminaries to others who would later become Cartesians themselves, such as André Martin and Nicolas Malebranche. Of particular note is Gibieuf. It was through Bérulle's influence that he rejected Molinism, to which he had shown some leanings, and through Bérulle's encouragement that he wrote his anti-Molinist book De libertate Dei et creaturae (1630), which argued that free will is essentially a matter of spontaneity. Years later, Descartes would make a point to tell Mersenne that he “wrote nothing [in the Meditations] which is not in accord with what [Gibieuf] said in his book De Libertate” (AT III 360, CSMK 179).

A second link between Bérulle and Descartes comes from a story told by Baillet, one that is often repeated although is unlikely to be entirely true. According to the story, in the fall of 1628 both Descartes and Bérulle attended a talk given by a Monsieur Chandoux. When the talk concluded, Bérulle noticed that Descartes alone did not applaud. Asked about this, Descartes replied that while he shared Chandoux's anti-Scholasticism, he did not think skepticism could be avoided if one did not begin with premises that were known with absolute certainty.