The Book of Rites is a diverse collection of texts of varied but uncertain origin and date, lacking the overall structure found in the other "rites" texts (the Rites of Zhou and the Etiquette and Ceremonial). Some sections consist of definitions of ritual terms, particularly those found in the Etiquette and Ceremonial, while others contain details of the life and teachings of Confucius. Parts of the text have been traced to such pre-Han works as the Xunzi and Lushi Chunqiu, while others are believed to date from the Former Han period."