To lead a philosophical life is to live a life devoted to reason—to live in accordance with one’s own deep and comprehensive understanding of how one’s life can be most fully lived. This is not about accepting a text or set of principles as authoritative. One must be committed to one’s own process of reasoning following arguments wherever they lead and implementing them. This is the existential commitment entailed by philosophy as a way of life.
But here is a worry. John Cooper argues that for the ancients correct philosophical reasoning leads us to a completely grounded philosophical understanding of the whole truth about how to live. Because philosophy provides the only access to the truth about what is valuable for human beings, it must govern life. This suggests that in order to lead a philosophical life one must have a fully worked-up, true theory of metaphysics, epistemology and ethics? But Cooper also emphasizes that it’s not a matter of following precepts. It’s through one’s own reasoning about what is good that one continuously structures one’s life.
“One was to live one’s life from, not just, as one could put it, in accordance with, one’s philosophy,” he writes.
But is it the possession of the correct theory that matters? Or is it the process of philosophical reflection that matters? Cooper seems to be arguing that the process of philosophical thought must be one’s guide but only on condition that it lead to the truth.
I’m much less confident than the ancients were that such a theory is available. There is no evidence that philosophy produces such a theory even after 2500 years of concerted attempts. Thus, if philosophy is a way of life, it can’t be because philosophers have fully developed true theories. To our contemporary minds, skeptical of claims to truth, it must be the process of philosophical thought that matters, not the truth status of its conclusions.
For me, what is most characteristic of philosophy is the comprehensive linking of subjectivity and what escapes subjectivity–the broader realm of cultural and moral values, meanings, facts about nature and human nature and, most importantly, the infinite realm of capacities, dispositions, and tendencies that make change possible. Philosophy is defined by its scope and its ability to synthesize these disparate domains. Philosophy is a way of life because it’s as large as life.
For human beings, the most persistent experience is of a chasm that opens between what is and what one wants, what one should want, and what can be. We experience these chasms at every moment, and when we fail to build bridges across them, life becomes horrific. Philosophy seeks linkages that enable us to reason across these domains. A question is philosophical because of its scope, its ability to draw questions and inferences from disparate domains of desires, facts, values, and potentialities.
What is problematic is the nature of those linkages across domains—I doubt we have a concept of reason or rationality that describes the required synthesis.
Philosophy: A Way of Life 