In this study, the author investigates, analyzes and evaluates the philosophically and politically important, interactive role played by criticism in forming and maintaining the concept of a democratic republic, and which played a fundamental role in the philosophical and political works of T. G. Masaryk, Emanuel Radl, Jan Patocka, Ladislav Hejdanek and Erazim Kohak. The study first describes Masaryk's concept of a democratic republic, which originated in his philosophical, social and political criticism of the time, and then continues with Radl's criticism of nationalism, also linked to Masaryk; Patocka's criticism of Masaryk's and Radl's philosophy and politics; and Hejdanek's and Kohak's criticism of Patocka's criticism. Philosophical criticism played an irreplaceable role both in the initial sustaining of Masaryk's and Radl's concept of a democratic republic and in its renewal and modernization. In the conclusion, the critical discourse of the authors discussed in the study is summarized.