The Commens Dictionary
Quote from ‘Pragmatism’
…every difficult mathematical theorem evidently involves some transformation of thought of which formal logic can take no account, although it is perfectly evident and undeniable, when it is suggested. This transformation, which creates an ens rationis, may appropriately be termed a “theo’ric” transformation.
MS [R] 318:22-3
From a possibly discarded variant.
‘Theoric Transformation’ (pub. 15.10.15-11:57). 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-pragmatism-81.