These days, 99.9% of the books, if ever got printed out, are better used for toilet paper than for reading. (So f*** arrogant!! - I take the blame, ok :)
I've never read this book, just "scanning"; the title and what you quoted, what in Wikipedia about the author (I read that page when answering this post). This book useless but will waste my useful time if I read - Will never read.
Good is good, bad bad. Period. Trying to sex up words is clever scheme to induce interest of the reader though. But it harmed the mind, instills extra delusions and hinderances - corrupting the true Buddha Dharma, especially by claiming: "
This is the basic teaching of Buddhism."
What truly useful, the wisdom, from real Buddhist teaching, is, "in good there is seed of bad, in bad seed of good." The ordinary can only see the good in good, bad in bad; the wise also the bad in (not "is"!!!) good, good in bad. Like the Chinese Yin-yang diagram Taiji, the black dot in the white, the white in the black - change. I-change (易經: I-Ching, how pre-telling the ancients able to pick the name, encompassing East and West). So, when the stock market swells, the vision it dipped; when bursted, foreseeing the boom. When life at the high, caution, time for downslope; at low, be alert, time for ascending soon; always keep your cool. Then you take the right action, with right attitude. This is what I called usefulness, real wisdom; not sexing-up words.
However, the pinnacle of comprehending, when qualified to utter: "good is bad, bad good, no difference", is when one able to truly dwelling in the state of Emptiness. Another word, Enlightened, Buddha-ed. But then the virtue is, silence. Period.
When one dwelling in Emptiness in real, he is able to transform - transform the physcial phenomena. A Chinese real Mahayana doctrine, "心能轉物, 即同如來" (When your citta/mind can turn the matter, you same as the Buddha), but is not learnt by other culture, yet.
Dwelling in Emptiness thus able to transform - legitimate to utter "good is bad, bad is good":
Mahisasakas Vinaya recounted a very ardent Upāsikā she cut piece of flesh from her leg (market closed) to make soup in urgency for a sick Bhiksu who needed meat as medicine. When the Buddha visited her family she dying, she excused not shown for didn't want to worry him. Yet the Buddha insisted, her husband had to carry her out. Just right at seeing the face of the Buddha, she lapped on her feet, recovered. Her leg and all reverted to as before like nothing happened. This the power of Emptiness the Buddha demonstrated, the meat cut from the leg was no difference from not cut - good is bad, bad good. The Vinaya recounted another, the Buddha himself washed an old sick Bhiksu who spilled his defecations and vomits all-over his body and room; dirty is clean, clean dirty, no difference. If those who uttered that kind of words, get qualified first, please! Else what gives that sitting on the "dharma platform" to teach? Why not a street sweeper also teaching "dharma" but you? Since, street sweeper and "dharma teacher" are, no difference, right?
In this respect, I think one first learning the Theravadin teaching far safer than parroting the Mahayana or Zen one. The Chinese Canon placed Agamas (counterpart to the Pali Nikayas) as the First Section out of the Twelves, means its importance, had to be learnt first. Otherwise fiddling with those Mahayana terms in ambiguous abstruseness can only induce the readers to in$till your pocket/ego and your "dharma Hall ~ of Fame"; but not instilling any real Buddha Dharma to their minds.