The Commens Dictionary

Quote from ‘Division III. Substantial Study of Logic. Chapter VI. The Essence of Reasoning’


An inference is a passage from one belief to another; but not every such passage is an inference. If noticing my ink is bluish, I cast my eye out of the window and my mind being awakened to color remark particularly a poppy, that is no inference. Or if without casting my eye out of the window, I call to mind the green tinge of Niagara or the blue of the Rhone, that is no inference. In inference one belief not only follows after another, but follows from it. [—]

If a belief is produced for the first time directly after a judgment or colligation of judgments and is suggested by them, then that belief must be considered as the result of and as following from those judgments. The idea which is the matter of the belief is suggested by the idea in those judgments according to some habit of association, and the peculiar character of believing the idea really is so, is derived from the same element in the judgments. Thus, inference has at least two elements: the one is the suggestion of one idea by another according to the law of association, while the other is the carrying forward of the asserting element of judgment, – the holding for true, – from the first judgment to the second. That these two things suffice to constitute inference I do not say.

1893-1895 [c.]
MS [R] 409:91-92; CP 4.53, 55
‘Inference’ (pub. 06.03.18-14:44). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
Mar 06, 2018, 14:44 by Mats Bergman
Last revised: 
Mar 06, 2018, 14:51 by Mats Bergman