FREGE'S CONCEPT PARADOX AND THE MIRRORING PRINCIPLE

Abstract

Frege held that singular terms can refer only to objects, not to concepts. I argue that the counter‐intuitive consequences of this claim (‘the concept paradox’) arise from Frege's mirroring principle that an incomplete expression can only express an incomplete sense and stand for an incomplete reference. This is not, as is sometimes thought, merely because predicates and singular terms cannot be intersubstituted salva veritate (congruitate). The concept paradox, properly understood, poses therefore a different, harder, challenge. An investigation of the foundations of the mirroring principle also sheds light on the role which language plays in Frege's epistemology of logic.