Sentence:  "Don't you see he is a lunatic, prince?" whispered Evgenie Pavlovitch in his ear. "Someone told me just now that he is a bit <WSD>touched</WSD> on the subject of lawyers, that he has a mania for making speeches and intends to pass the examinations. I am expecting a splendid burlesque now." 
Meaning of the word marked with <WSD> tags:  Slightly mentally deficient; touched in the head.