Peter Schouls examines the role played by the concepts of freedom, mastery, and progress in Descartes' writings, arguing that these ideas express a vital and fundamental feature of Descartes' thought. These theories also occupy a central position in the thought of the Enlightenment. Since the more contentious claim is that they function centrally in Descartes' works, Schouls presents a careful and detailed examination of the conjunction and use of these ideas in Descartes' writings. This examination warrants the conclusion that they play the same role in Descartes' works as they do in writings typical of the Enlightenment.

Schouls limits himself to a discussion of these three concepts in order to escape facile and vague generalizations. For the same reason, in relating Descartes to eighteenth-century thinkers, Schouls limits his attention to a single part of the spectrum of acknowledged Enlightenment reflection, the French "philosopes." From their writings he demonstrates that they are, and acknowledge themselves to be, Descartes' progeny.