In his "Miscellanies of the Old Student's Studio", Lu You (1125-1210) presents a misunderstanding of the term "He lun", which occurs in the context of the Tang-dynasty imperial examination system. Lu surmises that the term refers to a specific type of argumentative essay requiring the literary devices of comparing and contrasting. In fact, the term was used by Tang people as an abbreviation of He Yan's (d. 249) "Collected Commentaries on Confucius' Analects". In some cases it simply refers to the Analects itself. In the Tang-Song period, there were indeed essay questions needing to be answered in the form of comparison when making arguments in the imperial examinations. Nonetheless, no proper name was assigned to this specific essay type prior to the Northern Song (960-1127). It was often referred to as "the way to argue" ("ru he lun") in the Southern Song (1127-1279).