Fictions du diable focuses on the relationship between demonological treatises, literature and fiction, mostly in the sixteenth and seventeenth centuries, but not forgetting Saint Augustine, Leo Taxil or Collin de Plancy. Demonologists used various writing strategies, aware of their literary effects. Demonology also has a close link with fiction, in that it provokes debate on the limit between possible and impossible, which it does much to blur and redefine.