This article reassesses the links between the origins of the political economy and the Christian theology during the seventeenth and eighteenth centuries. I focus on the Jansenism movement-the most powerful Christian protest current in the pre-Revolution period. I reveal that the influence of this movement on economic ideas can be roughly divided into three issues. During the pre-Unigenitus (1713) period (first jansenism), (i) the original vision of labor that contrasts with the Protestant's approach and the Catholic doctrine, and (ii) the idea that self-interest can produce a social optimum were major contributions of the jansenism on economic debates. During the post-Unigenitus period (second jansenism), (iii) the confrontation between two parties-the "liberal" vs the "resistant" jansenism currents-on the interest-bearing loans issue led to the development of new economic arguments for or against the credit, while making reference to the Holy Writings.