The Book of Were-Wolves is a classic work of European lore on lycanthropy in particular pertaining to werewolves. The book deals with three subjects: 1) Summarizing folklore and beliefs about werewolves and related phenomena; 2) Collecting specific cases from ancient, medieval, and modern histories; 3) Explaining the origins of the beliefs and demythologize the superstition. The author treats the phenomenon of the werewolf as a psychological aberration, as essentially a delusional state. He also relates it to cannibalism and to the behavior of the notorious Norse berserkers, who would suffer from an insane battle rage. Speculations on the origin the various names by which werewolves were known in different European languages is intriguing, especially the idea that the term may derive from a word for an outlaw, a man condemned effectively to run with the wolves.