 The Logic ends with Part IV on method. The first three Parts of the book correspond to the tripartite layout of traditional logic texts. Part IV, however, constitutes an innovation reflecting the authors’ enthusiasm for the philosophy of Descartes and Pascal. Chapter 1 lays the groundwork in Descartes’ and Augustine’s rationalism, criticizing the role of the senses in providing knowledge, as well as the claims of Academic and Pyrrhonian skeptics. After spelling out the methods of analysis and synthesis in chapter 2, chapters 3 through 10 focus on the methods of geometry, including rules of definitions, axioms, and demonstrations. Chapter 11 then recapituates eight rules of scientific method. Finally, chapters 12 through 16 contrast the nature of rationally obtained knowledge with faith or belief.