As a philosopher Robert Nozick is mainly known for his 1975 book "Anarchy, State and Utopia" where he develops his arguments within political philosophy. But to me, it is one of his later books that has inspired me, and that is "The Examined Life--philosophical meditations" that came out in 1989.
This book contains about 25 essays that cover highly diverse topics even though they all have to do with how to live a life and the meaning of life. I read this book many years ago and it made a strong impact on me. I have recently started reading it again and realize even more that it has a lot to offer for anyone with an interest in design theory.
The basic theme in the book is the notion of reflection or examination. Nozick writes "examination and reflection are not just about the other components of life: they are added within a life, alongside the rest, and by their presence call for a new overall pattern that alters how each part of life is understood." This idea goes of course back to Aristotle and his famous notion about the "examined life". Nozick's book is an attempt to support such reflections and examinations of life in a way that is less philosophical (or theoretical) and more related to everyday experinces, such as, death, love, aging.
One of the core themes in the book is about value and meaning. Nozick devotes several chapters to the question about how we can know what makes something valuable and meaningful. All his reasoning resonates well with an everyday and intuitive way of thinking. For instance, he writes "Still, when all other things are equal, the more concentrated thought that goes into making something, the more it is shaped, enriched, and laden with significance." (p 14).
I have over the years used two of the chapters in the book in my teaching and also sometimes in my writing and that is the chapters "14. Stances" and "15. Value and Meaning". In our book "The Design Way" we use Nozick's model from chapter 15 as a way to discuss and analyze value and meaning when it comes to things and systems. This is a wonderful chapter and should be read by anyone who is interested in what makes an artifact or system valuable or meaningful. Nozick's analysis is simple, clear, and highly useful.
I know that a lot of people have problems with Nozick due to his early writings and his political views, but I find this book exciting and intriguing, and completely liberated from political philosophy. It has an style, tone, and language that you seldom find in book from professional philosophers. Another favorite example of a similar book in this style is Richard Rorty's "Philosophy and Social Hope". These are not typical philosophy books. They do not require the special and intricate knowledge and language of the professional philosopher, but they still rest on a stable foundation that can only be provided by someone who really knows the topic.