Bianhuobian 辨惑編 "Discussion of doubtful matters" is a critical treatise on superstition written by the Yuan-period 元 (1279-1368) scholar Xie Yingfang 謝應芳 (1295-1392), courtesy name Zilan 子蘭, style Guichao 龜巢, posthumous title Xie Wenqinggong 謝文青公. He hailed from Wujin 武進, Jiangsu, and decided to become a teacher, yet he refused an offer to become the director of the Qingxian Academy 清獻書院. During the last decade of the Yuan period he withdrew from official life and began literary studies in Baihe Creek 白鶴溪. His most important book except the Bianhuobian is called Sixianlu 思賢錄 "Records While Thinking of Worthies".
His 4 juan-long book Bianhuobian is dedicated to the dispelling of superstitious beliefs that were very popular in the region where Xie Yingfang originated and lived. Each of the 15 chapters concentrates on one theme of popular belief and explains in a question-and-answer pattern that supernatural occurrences are nonsense. Such are the belief in resurrection of the death, ghosts and demons, sacrifices to appease souls, prayers to avert or to heal diseases, fortune-telling by various methods, or the determination of auspicious or non-auspicious days. The book is ended by an appendix of eight texts of different character, most of them letters to his friends.
Educated in a Confucian manner, and thinking in logical and realistic terms, Xie Yingfang refused many beliefs of Buddhism and popular magic (fangshu 方術) that was deeply rooted in Daoism. These misbeliefs had caused greatest disaster: Emperor Wu 梁武帝 (r. 502-549) of the Liang dynasty 梁 (502-557) had starved because he feared the retribution of his sins from an earlier life, and Emperor Huizong 宋徽宗 (r. 1100-1125) of the Song dynasty 宋 (960-1279) had neglected the dynastic altars in favour to Buddhist temples and Daoist shrines. The author made extensive use of Chu Yong's 儲泳 (c. 1101-1165) book Quyishuo 祛疑說 from the Song period that also criticized irrational beliefs.