The Puritans coolly replied that they were not interested in the five propositions which the Pope had condemned, but that, as a matter of plain truth, they must protest against the ascription of these views to Bishop Jansen. So the war proceeded. It was at this time, in 1654, that the Jesuits made a ludicrous attempt to discredit their opponents by revealing the famous "Plot of Bourg Fontaine": a plot as rich in imagination and crude in fictitious detail as the Titus Oates plot. They had discovered, they gravely reported, that St. Cyran, Arnauld, and four other Jansenists had, twenty-three years before, met secretly in an obscure village to concert a plot for the destruction of Christianity in France. Arnauld was nine years old at the time given as the year of the conspiracy. Arnauld, from his solitude, issued a letter against the Jesuits, and (again packing the jury with monk-voters) they got it condemned by the Sorbonne. When we find the King writing to press the Sorbonne, we may clearly recognise the hand of the court-Jesuits. They triumphed, but their triumph now drew on them the heaviest and most enduring punishment they have ever suffered.
In 1648 the nuns had been compelled to return from Paris to their inhospitable valley, and the Solitaries had retreated from the abbey to a manor-house on the hill overlooking the valley. There, without any special costume or vows, a number of the most brilliant young men of Paris led a life of great austerity and devotion. Some lived in Paris, and spent an occasional period at Les Granges, and amongst these was a young man, with thin, pale face and large brilliant eyes under his lofty forehead, named Blaise Pascal. He had already won European fame as a mathematician. When Arnauld, somewhat jaded, produced a weak reply to his opponents, his friends suggested that Pascal should be asked to undertake the attack. Arnauld agreed, and on 23rd January 1656, appeared the first _Letter to a Provincial_. It was a subtle and irresistible satire of the theological shibboleths of the Jesuits. In order to enable the conflicting schools of monastic theology to agree in condemning the Jansenists, certain terms (such as "proximate grace" and "sufficient grace") had been introduced as vague common measures of orthodoxy, and Pascal expended his immortal wit on the weakness. It is admitted by all that the earlier _Provincial Letters_ are masterpieces of satire. The letter was received with delight in Paris, and a week later, while the debate continued at the Sorbonne, a second letter was issued. The third appeared ten days later, after the censure of Arnauld.