The origins of atheism as a philosophically articulated position have been conspicuously, but not accidentally, neglected by the historiography of metaphysics. Its earliest manifestations are to be found far away from the canonical texts of philosophy in the mostly unpublished philosophical underground literature, the littérature clandestine starting in the middle of the 17th century. In light of these sources, it is possible to reveal the roots of atheism in the history of theory and its relationship to the criticism of religion in antiquity, to deism, skepticism and rationalism as well as to the upheavals in the history of science during the epoch. The forty most important sources, most of them manuscripts, are presented in an appendix of literary history. A new afterword deals with the debates, some of which were quite fierce, which were triggered by this book. The research done during the past years has been documented in an updated bibliography.
