Similar ways of creating third concepts: Kant's "synthetic judgments a priori" and Frege's "thoughts"

Ingolf Max

It is well-known that Kant and Frege offer mutually exclusive answers to the (epistemo)logical status of equations. Expressions like "7 + 5 = 12" are synthetic (and a priori) for Kant but analytic for Frege. Nevertheless, Kant and Frege have a shared interest: Demonstrating the possibility of grasping a general realm by science. Kant question is "How is metaphysics as science possible?" Frege tries to answer the question "How is logic as science possible?" Both thinkers are convinced that a precondition for answering their questions consists in the creation of a third concept. But how? The mutually exclusive distinctions analytic vs. synthetic, a priori vs. a posteriori (Kant) and things (of the outer world) and ideas (of the inner world) seem to let no room for such a completely different third concept. The revolutionary idea is to create undefined basic concepts as molecules (patterns, Gestalten) with a characteristic inner structure opposed to atoms without any inner structure. Such molecules – Kant's "synthetic judgments a priori" and Frege's "thoughts" – can be used as connecting/intermediate pieces. The aim of this talk is to explicate the details of the molecular structure of Kant's and Frege's inventions and their mediating roles.