In September 1865 , Dostoevsky wrote a letter to Katkov . In the letter , he explained to him that Crime and Punishment was going to be about a young man who believes in `` certain strange , ` unfinished ' ideas , yes floating in the air '' . Nonetheless , forced by his situation , after all other appeals elsewhere failed , Dostoevsky turned as a last resort to Katkov , urging for an advance on a proposed contribution : In a letter to Katkov written in September 1865 , Dostoevsky explained to him that the work was to be about a young man who yields to `` certain strange , ` unfinished ' ideas , yet floating in the air '' ; he had thus embarked on his plan to explore the moral and psychological dangers of the ideology of `` radicalism '' .