The paper interprets the approach to the authenticity in literary theory and philosophy. At the start it mentions the concept of the authenticity as an opposite the fiction, the issue of authenticity of reality outside literature and the approach of the new censorship.
Subsequently it takes an adventage of the particular example of "authentic" literary diary of Ludvík Vaculík to demonstration of concrete opinions on authenticity in literary creation and in the end it applies the ethics of authenticity theory on the issue of literary diary.