I purchased the hardcover of this book in 1988. I read it cover to cover immediately. I used the rock setting techniques described by Slawson "hands on" in my landscape contracting business in Boulder, CO. I found it immensely useful.
A number of years passed, nearly four of them spent in graduate architecture school studying formal geometries, history, architecture as a verb.....architecture with a great big capital A.
Yet, I did not fully appreciate the book until recently. I dusted it off when I was hired to set 2 semi-truck loads of stones. I reviewed it and found that my studies from it ten years earlier had indeed made an indelible impression upon me. The seemingly daunting task of composing 50 tons of boulders in an aesthetically pleasing manner was made much easier thanks to Slawson's studies. His book was more useful than 3 1/2 years of architecture school. Believe me, read it and get your hands dirty. Work with big stones, the dirt. It is the real work.
You will likely find the book "thick" in the sense that at times, each sentence is filled with succinct words. You may find yourself re-reading sentences to understand. Better graphic descriptions could have helped here. In particular the sections comparing Arnheims "Art and Visual Perception" with compositional arrangements, proportions and general japanese garden aesthetics are excellent. It is in these sections where one begins to understand how intelligent japanese garden design is. It fully engages the haptic sense as well as one's psychology.
Slawson makes many important notes and observations about the making of Japanese gardens. Yet he also points out that Japanese gardens evolved in Japan because of particular conditions of culture and nature. He points out that the teachings would not necessarily recomend "copying" these teachings in other region with climates different than those of Japan.
Slawson gives us an excellent resource to consider Japanese "teachings" in composing gardens, for example, in the desert southwest (USA). A garden influenced by the desert southwest would simply not fit in Japan. Yet, if you make the "teachings" your own you could create a japanese influenced garden.
Similarly, many Japanese garden copies in America don't fit. With the exception of the Portland Japanese Garden in Portland, Oregon.
I recomend the book because I continue to turn to it year after year. The sign for me of a valuable book.
Patrick Healy