[dnquark]

I would say that quality is an abstract value judgement that requires context to be meaningful. That's why it escapes precise definition.

Whenever Pirsig talks about quality, it seems that he is heavily overloading the term. What he is really trying to do is develop a set of guiding principles that makes him feel like he understands the world and his role in it. Most people use religion or science for this, but Pirsig explicitly rejects science as a way of discovering the truth (for his definition of truth), and I think he implicitly rejects religion as well. I ended up reading "Quality" as just a label that he attaches to the personal philosophy he develops instead.