The author aims to explain the notion of rationality as an analytical tool. The main thesis is that rationality must be understood as a set of local rules. As rationality occurs in many cases, one can talk about pluralism of rationality. However, the author criticises the popular interpretation of ‘local rationality’ (Gianni Vattimo). He refers to the concept of language-games developed by Ludwig Wittgenstein. He advocates the conservative interpretation of Wittgenstein’s works, which is in contrast to the relativistic (Richard Rorty) and emancipatory (Lotar Rasiński) interpretations. The text can be treated as an exegesis of Wittgenstein’s theorem: ‘Thinking is surrounded by a nimbus. Its essence, logic, presents an order: namely, the a priori order of the world; that is, the order of possibilities, which the world and thinking must have in common.’