First part of the text presents a historical excursion searching for the genesis of Popper’s philosophical views in the interwar Vienna. It analyzes the actual writing process and circumstances that surrounded Popper’s work on Die beiden Grundprobleme der Erkenntnistheorie. The aim of this section is to evaluate Popper’s reception and intellectual self-development through the denial of logical positivism. The second “internalist” segment of this article further examines the Grundprobleme itself through the analysis of Popper’s specific interpretation of Kant’s transcendental idealism. We will confront Seubert’s claim that through Die beiden Grundprobleme der Erkenntnistheorie Popper definitely and knowingly accepts Kant’s stance. We show that even though Popper adopted Kant’s transcendental method of questioning, he had later criticized certain aspects of Kant’s transcendental method. As a result, Popper establishes the so called genetic apriorism, which dwells on his own version of the deductive psychology of knowledge.