Abstract
The conceptualization of periods in history is surrounded by many problems. What does it mean to identify a period by giving it a name, such as the Middle Ages or the Enlightenment? When does a period begin and end? Have St. Thomas Aquinas and Abelard something in common because they lived in the same period? Or Locke, Rousseau, and Kant? These and similar questions are usually studied by historians. Different answers are given when different sets of criteria are applied. Schouls uses three criteria to characterize the Enlightenment: freedom, mastery, and progress; three preoccupations which are joined together in the ideal of autonomy. Schouls applies the triad also to the philosophy of Descartes in order to find out whether or not that philosophy forms a part of the Enlightenment and its development. He analyzes the concepts of freedom, mastery, and progress in Descartes' philosophy and concludes that Descartes already articulated the triad and the corresponding ideal of autonomy. The eighteenth-century Enlightenment thinkers did little more than widely disseminate an inherited ideal. Instead of Bacon, Descartes has therefore to be considered as one of the principal founders of Enlightenment philosophy.