The Commens Dictionary

Quote from ‘The Logic Notebook’


The purpose of a Diagram is to represent certain relations in such a form that it can be transformed into another form representing other relations involved in those first represented and this transformed icon can be interpreted in a symbolic statement.

It is necessary that the Diagram should be an Icon in which the inferred relation should be perceived. And it is necessary that it should be insofar General that one sees that accompaniments are no part of the Object.

The Diagram is an Interpretant of a Symbol in which the signification of the Symbol becomes a part of the object of the Icon.

No other kind of sign can make a Truth evident for the evident is that which is presented in an image, leaving for the work of the understanding merely the Interpretation of the Image in a Symbol.

MS [R] 339:286r
Editorial Annotations: 

Corrected 2017/12/05 by Winfried Nöth

‘Diagram’ (pub. 13.05.16-12:07). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from
May 13, 2016, 12:07 by Mats Bergman
Last revised: 
Dec 05, 2017, 14:15 by Mats Bergman