Lie Zi (列子, pinyin: liè zĭ) or Lieh Tzu is a Daoist text that was inscribed in the imperial library's catalogue as Treatise of the perfect emptiness.
The author of this text is Lie Yukou. Please note that Lie Yukou is also called "Lie Zi".
It completes the famous Taoist trilogy with the more famous Lao Zi and Zhuang Zi. It is generally considered to be the most practical of the major Daoist works, compared to the philosophical writings of Lao Zi and the poetic narrative of Zhuang Zi.
Although Lie Zi has not been extensively published in the West, some fragments seem to be well-known especially to some scholars and other people who are interested in Chinese culture. The following excerpt is an example:
This applies not only to mastering archery, but mastering onself. Thus, the sage carefully examines -- not the fact of life and death, but its reasons.
The final two chapters of the Book of Liezi are of ambiguous nature. Chapter 7, Yung Chu, is condemned as very un-Taoist and in contradiction with the rest of the book. Translator Graham and the original commentator Chang Chan call this the hedonist chapter, due to its focus on women, drink, and indulgence of other pyshical and temporary pleasures. Graham attributes this section to a different author, though Chang Chan seems to suggest it was from Liezi's earlier years as a hedonist, before he began to follow the school of the way.
The final chapter, Explaining Conjunctions, is noted for almost being entirely based on quotes from other texts - including considerably pasages from Confucian and Mohist texts, two opposing philosophies, which contradict Taoist thought as expounded by the rest of the Book.
Of note is that throughout the text, 27 passages are taken from the Zhuangzi, and six directly from the Tao teh Ching. It is likely other texts no longer extant have been borrowed from as well, particularly in the eighth chapter.