Antoine Arnauld

Pascal was assisted in this task by Arnauld's nephew Antoine Le Maistre. Full text in original French : [1]
Grammaire générale et raisonnée contenant les fondemens de l'art de parler expliqués d'une manière claire et naturelle. Popular record for Arnauld's penetration was much increased in his L'Art de penser commonly known as the Port-Royal Logic which kept its place as an elementary text-book until the 20th century and is considered a paradigmatical work of term logic.

Not to be confused with his father Antoine Arnauld (lawyer) or his nephew Antoine Arnauld (1616-1698). He was one of the leading intellectuals of the Jansenist group of Port-Royal and had a very thorough knowledge of patristics.