This chapter deals with Dubislav's reconstruction of Bolzano's Kant criticism and his discussion of analyticity and analytic declarative statements (Sätze) which is central to Kant and Bolzano. Dubislav's views are discussed, namely that Bolzano anticipated modern mathematical logic, his examination of Bolzano's propositional functions, as well as the implications of other Bolzanian notions, such as derivability and probability. Bolzano's contributions are reconstructed and situated in the contemporary discussion by Bolzano's commentators. In regard to Dubislav's (Erkenntnis 1:408–409, 1931a) account of definition, his interpretation of Bolzano and Bolzano's replies concerning definition are reconstructed and evaluated. Dubislav brought Bolzano to the attention of the Berlin Group. The aim of this chapter is to reconstruct and evaluate their respective contributions to logic and philosophy for the current discussion in this volume.