This volume has a single goal: to argue that Descartes’s most fundamental discovery is not the epistemological subject, but rather the underlying free agent without whom no epistemological subject is possible. This fresh interpretation of the Cartesian “cogito” is defended through a close reading of Descartes’s masterpiece, the Meditations. Special attention is paid to the historical roots of Descartes’s interest in free agency, particularly his close ties to the French School of spirituality. Three aspects of Descartes’s personal evolution are considered: his aesthetic evolution from Baroque concealment to Classicism, his political evolution from feudal nostalgia to modern secularism, and his spiritual evolution from Stoic wisdom to active engagement in the world through the scientific project.