This paper is devoted to a detailed analysis of formal strategies in Miroslav Krleza's novel titled 'On the Edge of Reason' (Na rubu pameti, 1938). This famous Croatian writer looked for unconventional, more capacious than traditional novel forms of literary expression in his works of prose . His method was quite innovative for Croatian literary standards of the 1930s. It was based on a blend of different elements, primarily a combination of novel and essay structures. He integrated modern narrative techniques, philosophical digressions and numerous essayistic passages. In this way he improved, valued and increased the capacity of his works of prose. He created a novel where encyclopedic knowledge, polemical passion and literary fiction are integrated for a better presentation of Croatian cultural problems.