EN
The author recalls the controversy over the definability or indefinability of he concept of knowledge, more exactly, of the concept 'knows that', and presents a catalogue of arguments in favour of its indefinability. The main part of the article is a critical discussion of T. Ciecierski's (2013) view of what he calls "nastawienia sądzeniowe" (roughly, "belief attitudes") as being based on what he is prepared to dub an "elementary" truth, viz. the would-be truth of the claim that 'know that' is doxastically definable.