The Commens Dictionary
Quote from ‘Graphs, Little Account [R]’
Necessary deduction is that sort of inference in which the fact concluded is conceived to be involved in the facts premised. It is the reasoning of mathematical demonstration.
MS [R] S27:1
‘Necessary Deduction’ (pub. 18.03.18-12:41). 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-graphs-little-account-r-0.