Characterizing an intellectual tradition needs a comprehensive analysis of its major thinkers, if not all its relevant historical figures. Such a requirement is quite intimidating when writing a philosophically-minded intellectual history of Japan. It appears practically impossible for a single author to write a whole history of Japanese philosophical endeavor that covers a span of 1,400 years and various styles of thinking, without limiting the focus to certain areas such as religious or ethical traditions, aesthetics, and the like.

Such a bold attempt is undertaken in this book, subtitled A Short History. Professor Kasulis gives a comprehensive historical account of Japanese thought in terms of philosophy. Whereas he provides detailed discussion for only a few outstanding thinkers, nearly all the remarkable thinkers in the history of Japan – together with many historical or cultural figures – are briefly described as well. The author offers a consistent view of Japanese philosophy using his own theoretical apparatus that consists of such notions as engagement, mindbody, allocation, etc., to which we shall return shortly. It is undoubtedly courageous for a contemporary scholar to write an intellectual history that starts with Prince Shōtoku and ends with Sakabe Megumi, but the result is a stunning success – even though there is room for argument on several points, especially on the very idea of philosophy.

To give an overview of the book, it is helpful to describe the periodization and the figures featured. Kasulis uses a framework of four periods: the ancient and classical, the medieval, the Edo period, and the modern period. The ancient and classical period spans some six centuries up to the twelfth century, the medieval period features Kamakura Buddhism and Muromachi aesthetics, the Edo period highlights Confucianism and Kokugaku, and the modern period covers from the late nineteenth century onward. Each period features one or two philosophers to whom Kasulis gives a chapter-length account, and these featured “philosophers” are Kūkai, Shinran, Dōgen, Ogyū Sorai, Motoori Norinaga, Nishida Kitarō, and Watsuji Tetsurō. The author makes these seven figures the focus of his so-called “engaged” discussion.

Let us now extend the observation to two sets of notions that effectively guide the author's narrative. One is engagement/detachment, which is crucial to his idea of “philosophy” itself. Simply put, one has an “engaged” mode of thinking called philosophy as far as one has a constellation of significant problems and tries to solve them. The “detached” mode of thinking, on the other hand, takes an objective or scientific attitude toward knowledge. This latter mode of thinking, Kasulis argues, “became prominent in the West during the modern period of philosophy beginning in the seventeenth century” (p. 21). The book has accordingly two aspects, the engaged and the detached parts; detached knowers favor intellectual surveys that are sufficiently contained in this book, while engaged knowers are invited to take as their own matter the thought of the aforementioned seven philosophers. The book's uniqueness lies in the engaged parts that present the outstanding thinkers in a way that allows the reader to appreciate the problems or questions they addressed (Shinran's questions, Dōgen's questions, etc.) and their general approach in doing so. This approach makes the book unique and highly readable.

Kasulis uses another set of notions to show these common tendencies of Japanese thought: allocation, hybridization, and relegation. Hybridization is cross-pollinating of ideas from different traditions, while allocation “embraces the new by giving it a specified domain or role alongside the already accepted theories” (p. 36). Compared to these two types of argument, relegation “rejects the segregation of ideas found in allocation, but does not go as far as hybridization in creating something completely new. In relegation the preferred theory accepts intact a new or opposing theory but only by consigning it to a subordinate position within an enlarged version of itself” (p. 38). Among the three, relegation is considered the most noticeable mode of Japanese argumentation.Footnote ¹ Kasulis finds its exemplar in Kūkai's theoretical systemization of the ten mindsets and goes on finding it throughout history – in Yoshida Kanetomo's systemization of Shinto, in Nishida's logic of place, and so forth. This set of notions is independent of the other one – engagement and detachment – and is used effectively in the author's clarification of Japanese thought and philosophy.

By combining these sets of notions, Kasulis pinpoints the fountainhead of Japanese philosophy, which nevertheless seems to call for further consideration. For him, it is Kūkai who advocates engaged knowing and assimilates opposing views through relegation “as a riff, one of those classic riffs that every jazz or rock musician knows, but the origin of which is lost to history” (p. 137). This view results in the author's frustration with Nishida, blaming his ignorance of Kūkai: “Had he [Nishida] known Kūkai's theories, he might have been able to find a shorter route to his destination” (p. 460). But here a question arises: isn't the author's description of Japanese intellectual history overemphasizing the role of Kūkai?

There are two points to be noted regarding this question. First, the allocation/relegation argument obviously has its origin in Chinese Buddhism, most notably in the Tiantai theory of doctrinal classification. The author admits that Buddhist traditions “imported from China the stratagem of relegating the teachings of other schools into the lower tiers of their own inclusive system” (p. 38). While the doctrines of the six Nara schools are briefly sketched along with the featured Shingon doctrine, the Tendai/Tiantai doctrine is left almost untouched in this book – at least from a theoretical point of view. Second, it is by no means accidental but quite theoretical that Kamakura New Buddhists are affiliated to the Tendai school. In order to explain why this particular school served as a matrix for Kamakura Buddhism, the author cites the comment of a contemporary Tendai monk: “He noted that none of the religious leaders introduced into Japanese Buddhism a doctrine or practice that was not already part of Tendai at the time” (p. 163). This seems to suggest that those religious leaders in the Kamakura period have no necessary ties to the school, but there is fairly general agreement that Kamakura New Buddhism is deeply rooted in the Tendai/Tiantai doctrine. Considering these two points, it is tempting to find the philosophical “riff” elsewhere.

I would like to raise another question, regarding the author's conception of “philosophy” itself. Kasulis uses the term with a literary or existentialist bent, which differs strikingly from the contemporary understanding of tetsugaku in Japan. One can be a great thinker or a profound theorist, but cannot be called a “philosopher” without at least mastering the philosophical tradition of occidental origin; a fine example is found in another recent work on the same subject by a prominent researcher Fujita Masakatsu, who focuses on the modern period.Footnote ² Such a conception of philosophy seems unacceptable to Kasulis, who sees the premodern Japanese way of thinking “closer to the original vision of philosophy in the ancient Greeks like Plato and Aristotle than it is to the modern emphasis on an impersonal, incorporeal knowing” (p. 576). The contemporary Japanese usage of the term tetsugaku may be viewed as, to use the author's phrase, “intellectually and culturally colonized” (p. 579). It therefore remains uncertain if Kasulis's usage of the term will be warmly welcomed by philosophically minded readers, at least in Japan.

This conception of philosophy brings a noticeable tension into the author's description of modern Japanese philosophy. The “engaged” description of Japanese thought works well with premodern thinkers such as Shinran, Dōgen, Sorai, and Norinaga. On the other hand, it does not work well with Nishida, at least to the same extent. We may find that the metaphysical questions Nishida addressed are not so clearly described in Kasulis's account; we may feel something is wrong when the author expects Nishida to show interest in the revival of the premodern tradition by showing “persistent frustration over Nishida's not using the immense philosophical resources available to him from the premodern Japanese tradition” (p. 475). From this observation, we may notice that the author's “engaged” approach is not compatible with modern Japanese philosophy.

As I have said, it is courageous for a scholar today to write a comprehensive history of Japanese philosophy that starts with a legendary ancient prince and ends with contemporary philosophers. Such an unprecedented attempt cannot be immune to minor errors and small mistakes, which I will refrain from mentioning, but is also bound to bring with it a couple of bigger questions, as I have mentioned above. But I believe the reader will be rewarded by the author's readable presentation of Japanese intellectual history, which explores the question: what philosophy may mean in a non-Western context.