J R Patterson in New Humanist:
Zen and the Art of Motorcycle Maintenance, published in 1974, was nothing short of a cultural phenomenon. A work of fictionalised autobiography, the book follows its author Robert Pirsig on a long motorcycle ride through the US, from Minnesota across the prairie to Oregon, then down to southern California. The muscles of that skeletal journey are Pirsig’s philosophical musings on the notion of Quality. Pirsig created the concept in order explain the relationship between human values and societal values.
At once both obvious and ephemeral, Quality escapes easy definition. (And brings to mind American supreme court justice Potter Stewart’s comments about pornography: “I know it when I see it.”) In his original formulation, Pirsig describes it, not a little paradoxically, as “a characteristic of thought and statement that is recognised by a non-thinking or intuitive process.” At another juncture, Quality is defined as the event which occurs between the observer and the observed. Pirsig’s search for clarity stretched his mind to the breaking point, ultimately landing him in a psychiatric facility where he was subjected to electroshock therapy.
And yet, the concept has been influential. The book, a bestseller, continues to be read by motorcyclists, philosophers and everyone in between.