In 1902, Kraus published "Sittlichkeit und Kriminalität" ("Morality and Criminal Justice"), for the first time commenting on what was to become one of his main preoccupations: he attacked the general opinion of the time that it was necessary to defend sexual morality by means of criminal justice ("Der Skandal fängt an, wenn die Polizei ihm ein Ende macht", "The Scandal Starts When the Police Ends It"). Starting in 1906, Kraus published the first of his aphorisms in "Die Fackel"; they were collected in 1909 in the book "Sprüche und Widersprüche" ("Sayings and Gainsayings").