Peirce, C.S. (1878), "How to Make Our Ideas Clear", Popular Science Monthly, v. 12, 286–302. Reprinted often, including Collected Papers v. 5, paragraphs 388–410 and Essential Peirce v. 1, 124–141. See end of §II for the pragmatic maxim. See third and fourth paragraphs in §IV for the discoverability of truth and the real by sufficient investigation.
