Main Article Content
The paper “Lesniewski’s systems of logic” is devoted to three systems of logic of the polish logician St. Lesniewski. Lesniewski intended to construct the consistent foundations of mathematics, and then his strategy was fighting with the closure of the language and ability to control the system’s openness by the especial rules of the inference. In this paper we consider the systems of Protothetic, Ontology and Mereology, and also their peculiar features and Lesniewski’s contribution to the logic. We briefly describe the formation of Lesniewski’s systems and characteristic properties of each system.