As a proponent of the non-idealistic philosophy of language, more precisely, German philosophy of language, Kazimierz Twardowski was the intellectual pioneer of the theory of intentionality, truth, and predication. His aim was to develop a theory of scientific philosophy that would be characterized by vigor and exactness. While, on the one hand, Twardowski’s scientific philosophy may be portrayed as strongly intellectualistic, his approach was not scientistic. It is reasonable to argue that Twardowski owed his philosophical outlook to his tutor, Franz Brentano who inspired Twardowski to make distinctions between the object and the content of a presentation within the frame of reference of mental acts’ intentionality. Among his lasting contributions are (1) his formulation of the judgment-based theory of knowledge, (2) his conviction and elaboration of the concept of time-independent truth, (3) his concept of metaphilosophy, and (4) his emphasis on analysis as a viable method in philosophical deliberations. © 2022, Slovenska Vzdelavacia Obstaravacia. All rights reserved.