Reader's Encyclopedia


The 18th century. This period is variously called the Age of Reason and, in France, Le Siecle des Lumieres, because its writers as a whole applied reason to religion, politics, morality, and social life. Aside from purely historical events, the 18th century does not lend itself to a chronological view; its unity lay not in a coherent development or progression of ideas, but rather in the intellectual energy and enthusiasm which characterized its writers. Intensely aware of their heritage and dependency upon the ancients, these men clarified, sifted, and developed this heritage.

The rule of Louis XIV had been an oppressive one, and the somber religious tone which it took before the Sun King's death caused the reaction to it to be all the greater. The government, continued by the monarchies of Louis XV (1715-74) and Louis XVI (1774-93), fell ever deeper into discredit. The failure of John Law's Mississippi Bubble (a trade scheme of June, 1720), the increasing national debt due to royal prodigality, and the repeated hiring and dismissal of incapable finance ministers -- and even of capable ones like Cardinal Fleury, Turgot, and Necker -- all contributed to the economic instability of France. The necessity for reform became clear. The century culminated in the French Revolution, a crisis that reflected these economic and social ills; the application of reason to the human situation, so typical of the 18th century, perhaps made it clear to the middle class that the old order did not have to prevail. In most aspects of French culture, the influence of the increasingly economically independent bourgeoisie was to replace that of the aristocracy.

The Enlightenment began by breaking down the older forms of metaphysical and philosophical knowledge; Cartesianism, with its spirit of systems (esprit de systeme), was replaced by a systematic spirit (esprit systematique) -- the a priori by the a posteriori. In contrast to the 17th century, in which reason represented tradition, authority, stability, the 18th century saw reason as a tool, a means to authority. Questions were no longer envisaged under the aspect of pure thought, but were examined from a social and practical point of view. This preoccupation with the useful caused men to turn to the physical world; writers like Voltaire, Diderot, d'Alembert, and Montesquieu made literature out of the natural sciences, astronomy, law, travel, philosophy, politics, and education. The investigation into natural and social phenomena, what we would today broadly designate as science, was called philosophy in the 18th century. The philosophe (see philosophes) represented an ideal, as did the honnete homme in the 17th century, or as the universal man characterized the Renaissance. The philosophers of this age were in search of a concrete anthropology, a knowledge of man in general. This common goal by no means implied a homogeneous point of view: one has only to compare the differences between Voltaire and Rousseau, Buffon and Condillac, Diderot and Helv etius.

It is perhaps Condorcet who, in his Esquisse d ' un tableau historique des progres de l'esprit humain ( Sketch for a historical picture of the progress of the human mind, written in 1793-94), best summarizes the optimism and faith in human reason so characteristic of the age. In tracing man from the dawn of history, Condorcet first emphasized the liberation of mankind from ignorance, tyranny, and superstition by means of his science and his reason; he then sketched a hopeful future in which mankind would be free, equal in wealth, in education, and with sexual equality; he finally envisaged the moral, intellectual, and physical improvement, indeed perfection, of humanity that would arise through better instruction, laws, and institutions.