 In his 1878 paper, “How To Make Our Ideas Clear” (W3, 257–275) Peirce introduces three grades of clarity, or levels of understanding. In this paper, he introduces his famous pragmatic maxim as a development of rationalist notions of “clear and distinct ideas”. Combining his pragmatic maxim with notions of clarity from Descartes and Leibniz, Peirce identifies three grades of understanding. The first grade of clarity is to have an unreflective grasp of some concept in everyday experience. The second grade of clarity is to have, or be capable of providing, a general definition of that concept. The third grade of clarity, though, comes from Peirce’s famous statement of the pragmatic maxim: