The Commens Dictionary

Quote from ‘Book II. Division I. Part 2. Logic of Relatives. Chapter XII. The Algebra of Relatives’


The scholastic doctors used to talk of first intentions and second intentions. First intentions were conceptions obtained by generalizing ordinary experiences. Second intentions were conception[s] obtained by generalizing conceptions themselves considered as objects of logical comparison. Now an abstract notion, that is, the name of a quality, is the first fruit of second-intentional thought. I have therefore called that branch of formal logic which takes account of this operation, and expresses it, Second Intentional Logic.

MS [R] 418:359-60
‘Second Intentional Logic’ (pub. 22.08.15-18:07). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
Aug 22, 2015, 18:07 by Mats Bergman
Last revised: 
Aug 23, 2015, 22:35 by Mats Bergman