The Commens Dictionary

Quote from ‘Minute Logic: Chapter I. Intended Characters of this Treatise’


Argument is of three kinds: Deduction, Induction, and Abduction (usually called adopting a hypothesis). An Obsistent Argument, or Deduction, is an argument representing facts in the Premiss, such that when we come to represent them in a Diagram we find ourselves compelled to represent the fact stated in the Conclusion; so that the Conclusion is drawn to recognize that, quite independently of whether it be recognized or not, the facts stated in the premisses are such as could not be if the fact stated in the conclusion were not there; that is to say, the Conclusion is drawn in acknowledgment that the facts stated in the Premiss constitute an Index of the fact which it is thus compelled to acknowledge. All the demonstrations of Euclid are of this kind. Deduction is Obsistent in respect to being the only kind of argument which is compulsive.

1902 [c.]
CP 2.96
‘Deduction’ (pub. 02.02.13-10:16). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
Feb 02, 2013, 10:16 by Sami Paavola
Last revised: 
Jan 02, 2016, 16:16 by Mats Bergman