Jansenism is often considered as a intellectualized and individualized form of Catholicism. Yet his followers act collectively, especially in charitable activity. That is paradoxical at first sight because they are supporters of St Augustine and should value the divine grace (or predestination) against good works. But in Paris, most Jansenists are also notables (magistrates, big merchants and lawyers). The exercise of charity is therefore a long-established obligation for all of them and they spend time and money for that. In the age of Enlightenment, the Jansenists are perhaps the last to be as busy in charitable activity. By accomplishing this tasks, they also produce an alternative justification. Their zeil demonstrates the truth of their faith against the official clergy and associated social status and salvation.