This paper is an attempt at presenting the construct of open society as a consequence of the critical rationalist position. The above mentioned position was originally taken by Karl Popper on the basis of methodology of the (natural) sciences. If we accept this interpretation, which is quite different from Bryan Magee’s thesis (though at first glance seeming identical), it will be much easier to capture the factual “weaknesses” in Popper’s political philosophy. The historical context in which his reflections arose (especially his two books: “The Poverty of Historicism” and “The Open Society and Its Enemies”) was not without influence on his proposal, which the author treated as his personal contribution to the fight against the authoritarian and totalitarian ideology.