This study of the roots and expression of free thought in the Renaissance consists of three parts. The first is a overview of the history of dissident ideas up to and including the first part of the sixteenth century; the second is an examination and a new interpretation of the Cymbalum Mundi, probably by Bonaventure des Periers; the third is a presentation and interpretation of the Dialogues of Jacques Tahureau. Both works are seen to take their place as resurgences of a continuous though necessarily mostly covert current of dissident thought and feeling which was to well openly to the surface in the libertinism of the seventeenth century and be seen in full flood in the age of the Enlightenment. Many critics in the early years of this century and before have seen in the French Renaissance a time and period when such resurgences were fairly common. Others, particularly since the work of Lucien Febvre in the 1940s, have regarded these upwellings as imaginary, and have even denied the existence of the dissident tradition, viewing the whirlpools of the next century and the final tide-rip of the Enlightenment as spontaneously occurring phenomena with no reference to the history of ideas after the Classical period. Some remarkable recent work, none of it in English, has concentrated on establishing the existence of the dissident current itself, while considering its printed manifestations as either illusory or too obscure to establish with precision. The first part of the book describes succinctly the salient features of the dissident tradition, taking account of the indispensable but enormous and unwieldy theses of Busson and Berriot (both are available only in French, and Berriot's, whose sixteenth-century material is superbly documented, attends not at all to non-French scholarship), the brilliantly iconoclastic but politically biased work of Gerhard Schneider (available only in German and Italian), and the contributions of modern Italian scholars of the sevente