No single text could be considered more important in the history of philosophy than Descartes' Meditations. This unique collection of background material to this magisterial philosophical text has been translated from the original French and Latin. The texts gathered here illustrate the kinds of principles, assumptions, and philosophical methods that were commonplace when Descartes was growing up. The selections are from: Francisco Sanches, Christopher Clavius, Pierre de la Ramee (Petrus Ramus), Francisco Suárez, Pierre Charron, Eustachius a Sancto Paulo, Scipion Dupleix, Marin Mersenne, Pierre Gassendi, Jean de Silhon, François de la Mothe le Vayer, Charles Sorel, and Jean-Baptiste Morin.