Oráculo manual y arte de prudencia, by Baltasar Gracián, was published in Huesca in 1647. The treatise offered three hundred maxims succinctly commented on how to prosper in a society in crisis through prudence, sagacity and the wisdom of experience. This "art of living", which extended the values of the nobility to all literate individuals regardless of their status, anticipated the postulates of the Enlightenment. The extraordinary diffusion of this lay manual of moral philosophy was greatly helped by the success of its French translation at a time when French was the language of culture throughout Europe. Marc Fumaroli reconstructs in this essay the context in which Gracián's work and its French version were conceived, published and received after the Reformation, a time of fracture between reason and faith that split the restless conscience of Europe.