Blaise Pascal, The Jesuits And Jansenism

From an excerpt of a letter from Blaise Pascal.

To ascertain the matter with certainty, I repaired to my neighbor,M. N-, doctor of Navarre, who, as you are aware, is one of the keenest opponents of the Jansenists, and, my curiosity having made me almost as keen as himself, I asked him if they would not formally decide at once that "grace is given to all men," and thus set the question at rest. But he gave me a sore rebuff and told me that that was not the point; that there were some of his party who held that grace was not given to all; that the examiners themselves had declared, in a full assembly of the Sorbonne, that that opinion was problematical; and that he himself held the same sentiment, which he confirmed by quoting to me what he called that celebrated passage of St. Augustine: "We know that grace is not given to all men." I apologized for having misapprehended his sentiment and requested him to say if they would not at least condemn that other opinion of the Jansenists which is making so much noise: "That grace isefficacious of itself, and invincibly determines our will to what is good." But in this second query I was equally unfortunate. "You know nothing about the matter," he said; "that is not a heresy- it is an orthodox opinion; all the Thomists maintain it; and I myself have defended it in my Sorbonic thesis."
More letters (here)

Jansenism (here)
Pascal's bio (here)