This book is about as '70s as it gets. I kind of got the impression it might be '60s-ish, but it's much more in the '70s disillusionment phase. My general knowledge of the book before I read it was somewhat skewed, so I enjoyed it more than I thought.
The story is of a man crossing America on his motorcycle with his son, trying to reconnect with him. Philosophy gets discussed along the way. So far, so hippie, right? Well, actually, no. He's recovering from mental illness, and he's fundamentally very 'square'. He's an ex-scientist, a technical writer, and his 'motorcycle maintenance' is an exercise in care and logic. Indeed, it's the best description of debugging I've ever read, if only by analogy. Oh, and he's really rubbish at getting on with his son.
The book initially concentrates on the journey, but become increasingly concerned with philosophy, often through flashbacks into his fall into madness. The overall gist is in the direction of monism, through the underlying undefinable value of things - their Quality. It tries a bit hard, and never really clicks with me. I have a suspicion that any philosophy that proceeds step-by-step to astonishing solutions is probably wrong somewhere, a subtle wrong turn that just grows and grows. Useful philosophy is like a stable PDE - small inaccuracies don't make everything that follows useless. While his conclusions are odd, I like much of the journey, even if it's overwraught.
Much of this is concerned with a Poincaré-like view of the philosophy of science and maths. That is, all this talk of logic and reason is a sham! Specifically, while the results show rigour or experimental verification, the ideas come about through a creative process based around an intrinsic notion of beauty. While I think Poincaré knows about as much of the thought processes behind maths as a professional athlete knows of anatomy, I still feel there's a strong element of truth, which Pirsig links into Zen as being in a state of being fully absorbed into something - something I've come across elsewhere as 'flow'.
Anyway, the summary is that I like that bit, since it basically says the solution to the pains of a consumerist lifestyle is through gaining understanding and taking pride in what you do. Which fits pretty nicely in what I like anyway. Perhaps people read into this book what they like already? :)
At the end of it all, I think it's not terribly successful. It's highly ambitious, and has a good run at it, but I don't think it pulls it off. The philosophy doesn't sit right, and the story didn't really grab me either. It's impressively zeitgeisty with the anxiety of the '70s, and I'm glad I read it. In a way, one of the things I found most impressive were excerpts of letters in the back between the author and editor. It's clear the editor saw something in this way before it had its final form. The man obviously had fantastic vision.