The grouping is Zhu Xi's (
朱熹, Southern Song dynasty). He extracted
大学 and
中庸 from
《礼记》, paired them with
《论语》 and
《孟子》, and produced
《四书章句集注》 (1190). From 1313 (Yuan) until 1905 (Qing), the imperial civil-service exams drew their questions from this set with Zhu Xi's commentary as canon - meaning a thousand years of Chinese officialdom were filtered through these four short books.
