Wielowartościowość a pojęcia epistemiczne

The paper presents several attempts to express intuition concerning the understanding of knowledge and conviction by means of the conceptual apparatus of many-valued logic. J. Łoś’s pioneer system has been presented here, the system constructed by Ngoc Duc Ho, in which the internal logic in this system is used by the knowing subject as the three-valued logic of Łukasiewicz and the third logical value is understood as “unjustified”, and the four-valued system of N. Belnap, the system that allows for the occurrence of propositions which are evaluated both as true and false.