ABSTRACT
This chapter argues that the process is slightly different that the formalism of twentieth-century detective fiction comes about because the genre's interrogation of concepts of purity and hybridity eventually becomes turned on itself. It discusses Jacques Derrida's argument that genre is inherently impure. After the war, the detective genre tended more towards what Stephen Knight identifies as the clue puzzle' form, heightening its focus on the elements of the narrative that presented the reader with an intellectual challenge. Van Dine, however, seems more concerned about the incursion of other genres into detective fiction, particularly in his rule that no element of romance should intrude: There must be no love interest. It is indeed the case that the majority of writers did not adhere to these injunctions, but this does not mean that the rules did not have some influence on detective fiction, nor does it explain why these codifications came about in the first place.
