The Commens Dictionary

Quote from ‘Minute Logic: Chapter II. Section II. Why Study Logic? ’


In place of the percept, which, although not the first impression of sense, is a construction with which my will has had nothing to do, and may, therefore, properly be called the “evidence of my senses,” the only thing I carry away with me is the perceptual facts, or the intellect’s description of the evidence of the senses, made by my endeavor. These perceptual facts are wholly unlike the percept, at best; and they may be downright untrue to the percept. But I have no means whatever of criticizing, correcting or recomparing them, except that I can collect new perceptual facts relating to new percepts, and on that basis may infer that there must have been some error in the former reports, or on the other hand I may in this way persuade myself that the former reports were true. The perceptual facts are a very imperfect report of the percepts; but I cannot go behind that record. As for going back to the first impressions of sense, as some logicians recommend me to do, that would be the most chimerical of undertakings.


The data from which inference sets out and upon which all reasoning depends are the perceptual facts, which are the intellect’s fallible record of the percepts, or “evidence of the senses.” It is these percepts alone upon which we can absolutely rely, and that not as representative of any underlying reality other than themselves.

CP 2.141-3
‘Perceptual Fact’ (pub. 20.07.15-19:37). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
Jul 20, 2015, 19:37 by Mats Bergman
Last revised: 
Jul 20, 2015, 19:39 by Mats Bergman