Antoine Arnauld

Antoine Arnauld, called le Grand to tell him from his father, was a French Catholic theologian, priest, philosopher and mathematician, born in Paris on 6 February 1612 and dying on 8 August 1694. The youngest of twenty children, he studied theology at the Sorbonne and became a leading intellectual of the Jansenist circle at Port-Royal, defending it in controversy with the Jesuits and later living in exile in the Netherlands and Brussels. He was among the first to adopt the philosophy of René Descartes, and his L'Art de penser, known as the Port-Royal Logic, remained an elementary textbook until the twentieth century and is considered a paradigm of term logic. He was regarded as important among the mathematicians of his time, one critic calling him the Euclid of the seventeenth century.