
This book presents a history of spiritual exercises from Socrates to early Christianity, an account of their decline in modern philosophy, and a discussion of the different conceptions of philosophy that have accompanied the trajectory and fate of the theory and practice of spiritual exercises. Hadot's book demonstrates the extent to which philosophy has been, and still is, above all else a way of seeing and of being in the world.
* The Inner Citadel/Philosophy as a Way of Life by Pierre Hadot
* Plato's dialogues (someone already mentioned a few of them, but the Republic was missing from their list).
* Epictetus (Discourses and Enchiridion)
* The various essays/letters of Seneca
* Matter and Consciousness by Churchland (older, but fascinating)
* The Mediations of Marcus Aurelius
* (mostly) any Buddhist texts
* What a Plant Knows
* Moonwalking with Einstein
There are tons of fascinating books, way too many to list.
However, I'll make one concrete recommendation: Philosophy as a Way of Life by Pierre Hadot. It's about the ancient Greeks and the Stoics and the particular ways they saw thinking as bound up with living. It's a serious book but beautifully written.
It is discussed more at length in this list of 5 "life-changing" philosophy books.
https://fivebooks.com/best-books/life-changing-philosophy-bo...
fivebooks.com is a great site where they ask people to recommend five books on their area of expertise and explain why they picked each one. They have a philosophy category and it's organized by topic, including "How to Live".
If you return to the ancients, living philosophically was more important than the conceptual edifice or system building we conceive of as philosophical today--that's why we run into somewhat blatant contradictions in the systems of the neo-platonists and others--it is not that they were necessarily poor systematizers and let their concepts run away from them--that man didn't quite have the same intellectual power for reasoning cleanly yet--but that systemic clarity was not their goal--they had only an effect in mind.
The ancients were almost therapists in a sense--their whole goal was to get one living in the right way--thus few of them actually bothered to write as the philosophical schools were centered on practices, rituals, meditations etc.--progressions--and not just explication--exegesis of a master's thought was important--but only to the extent it had a direct impact on one's life and the way one lived. A philosopher, to the ancients was simply anyone who lived in a certain way--and by certain principles, whether or not they had conceived of those principles or learned them--the designation came with the living and the way not with intellectual output, but with intellectual activity(living with a love of wisdom). There's a reason Epictetus's text is called Enchiridion, which means manual or handbook--the same can be said of the use of the word Sutra
Then the middle ages hit and philosophy became far more theoretic as it was subordinated to theology--it became the so called handmaiden of theology--now its whole purpose was conceptual clarification, system building, logic--in order that one might know God, might develop a theological framework, put all the cosmological ducks in order.
I scarcely have to describe how the analytic tradition in the 20th century drove this notion of philosophy primarily as systematizing, abstract, and having little connection with one's actual practice and way of living further, and indeed to an extreme. As someone once enmeshed in the analytic tradition myself, I find nothing more distasteful than stuffy academic philosophy--it is necessary sure, but we must recall that philosophy was foremost supposed to teach one how to live (or how to die ;) ).
Wittgenstein is perhaps the only "analytic" that offers a philosophy similar to those of the ancients--You'll find that even the Tractatus, which helped birth the most arid and abstract form of philosophizing, logical positivism, if you read it carefully, is actually a text meant to directly influence the way you live and resolve some problem of living more than it is the presentation of some metaphysical, logical framework--indeed, the propositional structure of that text is more or less a smokescreen--W., like Socrates, like Nietzsche, presents a mask--remove the numbers, re-title it "Aphorisms"--has anything changed?
Hadot's book, Philosophy as a Way of Life is a great study on this shift from philosophy as lived, therapeutic practice to philosophy as a primarily textual, abstract, academic profession--and like all professions, limited by exterior considerations.
I'm not a big fan of Guide to the Good Life either -- mostly because I think it takes a very profound (and by no means simple or obvious) set of ideas and reduces it to a kind of intellectual fad diet.
For something weightier, you might look at the works of Pierre Hadot (Philosophy as a Way of Life and What is Ancient Philosophy?), both of which contain excellent discussions of stoicism.
