the eighteenth century was a period in the history of civilization, and especially in that of medicine, which occupies a distinct if not a detached position in the historical evolution of medical thought. Whereas the seventeenth century was dominated by political and social movements and by an orientation toward free investigation, the eighteenth represents a logical evolution of facts and ideas in their most ample and complex manifestations. It ended with a great political reaction against dominant institutions, a reaction determined by a spirit of revolutionary idealism which tended more and more to the liberation of peoples and of individual consciences. This idealism found its spiritual origin in a decisive orientation toward the natural and exact sciences and in the dominance of inductive philosophy.