The Commens Dictionary
Quote from ‘Miscellaneous Fragments [R]’
An Index is a sign whose signative virtue resides in its factual relation to its object. Certainly, not everything that is in factual relation to another, or is seen to be so, is thereby an index of that other.
MS [R] S104
‘Index’ (pub. 26.08.17-16:46). 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-miscellaneous-fragments-r-8.