On Quality: An Inquiry into Excellence is a collection of unpublished texts, speeches, letters, interviews, and private notes by Robert M. Pirsig, along with key excerpts from his famous work, Zen and the Art of Motorcycle Maintenance . Edited and introduced by Wendy K. Pirsig, Robert's wife of four decades, the book offers a deeper understanding of the concept of Quality that became central to Pirsig's philosophy.

Published more than a decade before Zen and the Art of Motorcycle Maintenance, On Quality explores the ideas that Pirsig would later expand upon in his groundbreaking work. The core concept of the book is Quality, a term Pirsig uses to describe a fundamental rightness or excellence that underlies all of existence. He saw Quality as akin to the Buddhist ideas of dharma or the Tao.

Here are some key points about On Quality

• It delves into the nature of Quality: The book explores Pirsig's concept of Quality in more detail than Zen and the Art of Motorcycle Maintenance. Pirsig argues that Quality is not a thing or an idea, but rather an experience – the felt sense of rightness or goodness that arises when subject and object meet.
• It offers a window into Pirsig's development as a thinker: The unpublished writings and letters included in the book provide valuable insights into Pirsig's intellectual journey. They show how he grappled with philosophical concepts and how his ideas about Quality evolved over time.
• It sheds light on Pirsig's personal struggles: The book also touches on Pirsig's struggles with mental illness, which are alluded to in Zen and the Art of Motorcycle Maintenance. These insights can help readers to better understand Pirsig's unique perspective.

On Quality is a valuable resource for anyone interested in Pirsig's philosophy or in the concept of Quality itself. It is also a fascinating read for fans of Zen and the Art of Motorcycle Maintenance who want to learn more about the man behind the book.