Abstract
This paper is a contribution to the history of ethics, being an account of an episode in the detachment of ethics from religion. According to certain 17th century Jesuits, a person who does not know or think of God can commit only a ‘philosophic or moral’ sin which cannot deserve eternal punishment. Arnauld’s attack on this ‘Philosophism’, and on the idea that to deserve blame one must know one is doing wrong, touched on voluntariness, intention, conscientiousness, sincerity, the justice of God’s helping some and not others, the requirement to do the right thing for the right reason, and other matters related to wrongdoing, blame, punishment and excuses.