4.5*
I read this excellent book based on the immense strength of his previous work "The Overstory" (https://www.goodreads.com/review/edit/40180098) - I've seen it described as a type of indirect sequel or companion book, and I can see why that has been said.
I would cast it as dark near future sci-fi built around a truly touching father & son story.
The sci-fi element is inventive, well thought out and tragic. The father & son story, based on deep loss and the immense difficulties of the son's 'neuro-divergence' (the father refutes the 'autism/on the spectrum' labels) is brilliant.
This relationship serves as a vehicle for damming facts and realities about the real world over-medicalisation of children and our growing list of environmental calamities.
The sections in nature are wonderful, following on from "The Overstory" as are the speculative descriptions of the many exo-planets we visit during the story. This step up from Earth into space (a little like "The Passenger" by Cormac McCarthy) is well received by this reader, a cosmic view on life, the universe and our place in it. The possible solutions to Fermi's paradox are dark, but not McCarthy dark!
My only slight issue with the book is a kind of cartoonish political situation that develops during the second half of the work. I say cartoonish, but several elements have kind of taken place in the US already. Strongmen, refusal to accept election results, science bashing, the growing power of religious extremists...well, he may be on to something, but it's not presented subtilty. A loud warning that may seem out of place with the rest of the book in a few years - hopefully.
The name of the book seems to be from this section "Only pure bewilderment kept us from civil war" I thought this was strange as so much of the book concentrated on the father and son getting back to nature (as we all should!), and the wonder and tragedy found there, maybe it's a dual meaning.
For me, the book was reminiscent of Kazuo Ishiguro's "Never Let Me Go" (https://www.goodreads.com/review/edit/6334) except the excitement and quality of the writing is clearly better than the Nobel prize winners book. Recommended.