What Makes a Reasoning Sound?

Seventeenth Selection, pp. 242-257.

MSS 448-449. [Partly published in CP 1.591-610 (MS 448), 1.611-615 and 8.176 (MS 449).]

Origin of the Text

Delivered on Monday, November 23, 1903, this is the first of eight lectures Peirce was invited by A. Lawrence Lowell, in mid-March 1903, to give at the Lowell Institute in Boston during the fall. The title for the course was "Some Topics of Logic bearing on Questions now Vexed." The first lecture was probably composed in late August-early September, and several drafts have survived: the first in MS 447, the second in MS 452, the third in MS 451, and the fourth in MS 453. The text in EP2 combines two notebooks that at first do not appear continuous, since MS 448 ends on p. 48 and MS 449 begins on p. 37. Careful analysis shows, however, that Peirce probably jumped from the near end of page 37 in MS 448 to MS 449; the transition is excellent, and weakens two other possibilities: that MS 449 might have continued in MS 553 (which ends on a p. 37), or that MS 449 follows a notebook that no longer exists. An important addendum—an answer to a listener's question about the first lecture that Peirce provided at the beginning of his third lecture—has been printed in the notes.