A sequence of witty epistles uses satire and clear argument to criticize Jesuit casuistry and defend Jansenist claims, exposing moral laxities and theological evasions. Each letter analyzes doctrines such as probabilism, the method of directing intention, and notions of grace, pardon, and moral responsibility, citing contemporary casuists and hypothetical cases to show practical consequences for confession, almsgiving, and judicial ethics. The prose combines ironic ridicule with juridical reasoning, bringing together polemic, textual citation, and anecdote to challenge religious authority and ethical compromises.