조선시대 문신 장유(張維, 1587~1638)가 평소에 보고 들은 한시, 문장 등에 대해 고증과 비평을 모아 편찬한 수필 평론집이다. 장유는 성리학의 편협한 학문 풍토를 비판했고, 지행합일(知行合一)을 주장하면서 마음을 바로 알고 행동을 통해 진실을 인식하려 했던 양명학적 사고방식을 가진 인물이었다.

A collection of critical essays by Jang Yu (1587–1638) from the Joseon Dynasty, which included empirical research and criticism of records that he read or picked up from classical Chinese poems, and prose. Jang Yu was a figure who criticized the narrow-minded climate of neo-Confucianism. He had the attitude of Yangming School that advocated the agreement of knowledge and action to recognize the truth by knowing one’s mind and taking action.