The Commens Dictionary
Quote from ‘A Syllabus of Certain Topics of Logic’
The line of identity is a Graph any replica of which, also called a line of identity, is a heavy line with two ends and without other topical singularity (such as a point of branching or a node), not in contact with any other sign except at its extremities. Otherwise, its shape and length are matters of indifference. All lines of identity are replicas of the same graph.
Peirce, 1903, p. 22; CP 4.416
‘Line of Identity’ (pub. 18.03.18-17:08). Quote in M. Bergman & S. Paavola (Eds.), The Commens Dictionary: Peirce's Terms in His Own Words. New Edition. Retrieved from http://www.commens.org/dictionary/entry/quote-syllabus-certain-topics-logic-34.