Nicolas Caussin (1583–1651) was a French Jesuit, a theorist of the passions. His treatise, The Holy Court Fourth Tome, was published in 1638. This work gives a Christianized account of what he calls the four principal passions: Love, Desire, Anger, and Envy, as well as many variants and subgenres of these types. The intent of the work is to instruct the proper means for controlling these affects.
Born in Troyes, Caussin entered the Society of Jesus in 1609, and became Louis XIII's confessor from March to December 1637. Reputed as a rigorous spiritual director who opposed, in the words of the Jansenist Antoine Arnauld, "attrition, arising from the fear of hell alone (...) as there could be no justification without love of God". Although the Catholic Encyclopedia of 1913 claimed that this was not the cause of his disgrace with Cardinal Richelieu, who sent him in exile to Quimper, this cause has been recently re-asserted by Philippe Sellier and Gérard Ferreyrolles in their new edition of Pascal's works.
He returned to Paris in 1643, following the death of Richelieu, and his reputation led him to be chosen to respond to the critical Théologie morale des Jésuites (Moral Theology of Jesuits), published by Arnauld, successively publishing in the second half of 1644 the Apologie pour les religieux de la Compagnie de Jésus, à la reine régente and the Réponse au libelle intitulé La Théologie morale des Jésuites. Due to his rigorism and to the formulations in those books justifying the "relaxed moral" concerning confession, the public generally considered that he had written against his thought by fidelity to his jesuit order.