The Commens Dictionary
Quote from ‘Minute Logic: Chapter III. The Simplest Mathematics’
Mathematical logic is formal logic. Formal logic, however developed, is mathematics. Formal logic, however, is by no means the whole of logic, or even its principal part. It is hardly to be reckoned as a part of logic proper.
‘Formal Logic’ (pub. 04.05.15-19:51). 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-minute-logic-chapter-iii-simplest-mathematics-3.