A murderer or madwoman quarantined( 被隔离 ) in a book on the bedside table can provide excitation( 刺激 ) and cautionary( 警告的 )reading , but an essayist, being his own protagonist ( 故事的主角 ), should be faceted rather like a friend. We might give him our keys and put him up in the guest room...after sleeping on our problems, he will sit at the breakfast table in the morning sunshine and tell us what we ought to do. The book mentioned in the first sentence most probably belong to the genre(s) of _____.