The Commens Dictionary

Quote from ‘A Brief Intellectual Autobiography by Charles Sanders Peirce’


…he divided all reasoning into, 1st, the deductive, including all necessary inference together with all probable inference to which the calculus of probabilities is properly applicable (rejecting inverse probabilities not founded on positive information), 2nd, the inductive, including all experimental testing of hypotheses (for he considers a physical experiment to be in a general sense of the same nature as a geometrical reasoning, which is performed by internal experimentation) but excluding, 3rd, the “abductive,” or the process of forming and accepting on probation, a hypothesis by which to explain surprising facts.

Peirce, 1983, p. 65; MS [R] L107:3-MS [R] L107(s):6
Editorial Annotations: 

This quote has been taken from Kenneth Laine Ketner's 1983 reconstruction of Peirce's 'Autobiography'

‘Abduction’ (pub. 14.03.18-12:49). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
Mar 14, 2018, 12:49 by Mats Bergman
Last revised: 
Mar 14, 2018, 13:00 by Mats Bergman