The First Rule of Logic

Fifth Selection, pp. 42-56.

MSS 442 AND 825. [Published, in part, in CP 5.574-589 and 1.135-140, and with some variations in Reasoning and the Logic of Things, pp. 165-180.]

Origin of the Text

This is the fourth of the Cambridge Conferences Lectures, which Peirce delivered on February 21, 1898. William James, who had read it a month earlier, told Peirce it was "a model of what a popular lecture ought to be" and implored him "on bended knees to give it first." Peirce instead rewrote his first lecture and kept this one in its fourth place, but altered it with many revisions. He deleted a number of passages, mostly because of time constraints (all but two have been restored), and added seven paragraphs (the three pages of MS 825, which begin the famous statement of the one rule of reason, "Do not block the way of inquiry") that have been inserted at their most likely place in the middle of the lecture.