The Commens Dictionary
Quote from ‘A Suggested Classification of the Sciences’
I divide the sciences of discovery into, 1, Mathematics, which traces out the consequences of hypotheses without concerning itself with their truth, and as the business is carried on, also formulates these hypotheses to represent in some measure confused statements of supposed fact (or fancy); 2, Philosophy, which deals with positive truth, but only so far as it is discoverable from ordinary everyday experience; 3, Idioscopy, or Special Science, which business chiefly consists in observation.
MS [R] 1339:6
‘Idioscopy’ (pub. 04.05.15-18:45). 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-suggested-classification-sciences-1.