This book is the result of a series of discussions that took place in Tokyo in 2016 between two Zen priests, Fujita Isshō and Yamashita Ryōdō, both ordained in the somewhat radical lineage of “Homeless Kodo,” and the popular and prolific Japanese philosopher, Nagai Hitoshi. The framework of their conversations is what Fujita and Yamashita call “Buddhism 3.0,” a reformist attempt to combine the clear blue sky of traditional Zen meditation (Buddhism 1.0) with the approach of “mindfulness” (Buddhism 2.0). They engage with Nagai’s phenomenological-experiential solipsism by debating Uchiyama Roshi’s idea of an original, all-encompassing Self and examining the transition from that singular, monistic “I” to a compassionate openness to others.
There is a creative and playful atmosphere with this book where two monks and a philosopher discuss this idea of "Buddhism 3.0", which is trying to reconcile typical Hinayana and Mahayana approaches to Buddhist practice through Nagai's solipsistic philosophy. This produces some fruitful insights. For example, the importance of context for meditation practice - getting the "Right View" straightened out so that one's meditation practice actually works.
However, the book and idea of Buddhism 3.0 is very much a work in progress, meaning that the reader is left with more questions than answers (this is not inherently a bad thing, but it is a bit less satisfying). The monks maintain that this can't be understood without meditation, and the philosopher also says that reading this book won't help you to understand his philosophy. Overall it left me with the impression of this book being more of a taster to something else rather than complete unto itself. Given the subject, I also can't really tell if the philosopher is really onto something or not. It's quite opaque. He also comes across a bit arrogant to me, at times calling Buddhism "primitive" and claiming he is the first/only to talk about this topic.
Overall, like many attempts to marry philosophy with Buddhism, I am reminded by the Buddha's thicket of views. The spiritual life is, in my mind, an iterative process where knowledge and practice feed into each other over time. But simply establishing Right View once and for all and then practising is not sufficient. However, it was a generally enjoyable read with some good nuggets for those interested in Zen, existential philosophy, and the like.