The Value of Two Extant Song Dynasty Block-printed Editions of Zhou Dunyi wenji

Though Zhou Dunyi wenji has varied editions,two valuable block-printed ones in the Song Dynasty have not been paid much attention and fully employed by scholars yet.Their value is demonstrated in two aspects: Firstly,they have fairly kept Zhang Shi's long-lost Taiji tujie(explanation of the Supreme Ultimate Diagram),providing new materials for studies of Zhang Shi's idea and its evolution;Secondly,many rare poems and essays of the Song Dynasty can be found in the two editions,making a useful supplement and collation to some books of the Song Dynasty,especially to The Complete Poems of the Song Dynasty and The Complete Works of the Song Dynasty.