A study of the evolution and relevant social context of philosophical ideas on progress, science, nature, and metaphysical faith of reason. Specifically examines the views on progress of Descartes and Pascal in the seventeenth century, the views and influences of French philosophers during the eighteenth century Enlightenment, the use of essential elements in the Cartesian ideas of science and progress, and the relationship of science to society and morals. Includes analysis of philosophers such as Diderot, Voltaire, D'Alembert, Turgot, Condillac, Rousseau, Fontenelle, and Condorcet.