Slingerland is one of several scholars (R. T. Ames, S. Cook, PJ Ivanhoe, E. Molgaard, J. Paper, V. Mair among others) reinvigorating Western scholarship on early Chinese thought. Readers of New Age interpretations steer aware from genuine scholarship, but perhaps they - and other general readers - should take a look at this book as a pathway to expertise on the field. The early texts in question, such as Kongzi's (Confucius') "Analects" and the Zhuangzi (Chuang Tzu) are hard to read and interepret. One reason that Slingerland manages to make them accessible is his focus on their central (spiritual) metaphors. As he argues, there is much that is universal in the structure of metaphors from any time or place. As an overview from a spiritual perspective, I strongly recommend this well-organized, thoughtful book.
As a non-specialist, I found this a very readable journey through ancient Chinese philosophy: from the Analects to Xunzi via the Daoists, following the thread of wu-wei or comparable metaphors of relaxed states. I found this book comparable in scope and quality to Chad Hansen's "Daoist Theory of Chinese Thought", although Edward Slingerland does not define himself as a Daoist. His use of the new field of "conceptual metaphor" is remarkable: it says that the basic metaphors in various cultures arise from the body and its movements; like walking, moving (effortlessly, on a Way...) or through simple actions of daily life, like filling a container with water, that triggers the metaphor of the true Self as a container, that is filled with an artificial social self of desires (ego) that to a Daoist must be emptied to allow the Dao to fill the true Self. Incidentally, this also could provide a solid basis for C.G. Jung's cross-cultural archetypes, that are in fact such metaphors; I'm thinking of his studies of metaphors in the I Ching for example (although E. Slingerland does not discuss Jung in his book.)