Digital Companion to C. S. Peirce
1907 | The Fourth Curiosity | CP 4.647-8
A character which is not sometimes true and sometimes false of the same singular is a kind. A kind may not exist at all; or it may exist in but one sole singular, which the old logics used to say was the case with the kind called sun. [—]
I consider a kind to be an ens rationis, although that may be open to dispute, at least as regards some kinds; but there can, I think, be no doubt that a class is an ens rationis. For a class, unlike a kind, is not a character, but is the totality of all those singulars that possess a definite existent character, which is the essential character of the class.
‘Kind’. Term 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/term/kind, 24.03.2023.
Class | Collection | Natural Kind | Character