James Miller:

The moral of these philosophical biographies is therefore neither simple nor uniformly edifying. For anyone hoping for happiness, or political wisdom, or salvation, philosophical self-examination seems in practice to have led to self-doubt as often as self-trust, to misery as often as joy, to reckless public acts as often as prudent political conduct, and to moments of self-inflicted torment as often as moments of saving grace.

I found myself thinking, as I read his book, about this gap between theory and practice and wondering if maybe the problem is in the folly of ever thinking that the raging floodwaters of life can be tamed and neatly channeled by rational principles in the first place. Socrates/Plato was wrong about many things; what if the idea of intellectual consistency being a prize virtue is another? What if the attempt to define people by unbending logical principles is just as misguided and doomed to failure as the search for some mysterious essence called the soul to define them by? What if the True, the Good, and the Beautiful do not necessarily harmonically converge?
Imagine my chagrin, a few paragraphs later, to find Rousseau, one of my least favorite philosophers, forcing me to grudgingly tip my hat to him:

When Montaigne tried, and failed, to emulate the stoic composure of Seneca, and chose instead to describe himself as he really was in his Essays, he was finally able to step outside the tradition of moral perfectionism that had linked the philosophical ideals of Socrates and Plato to those articulated by Seneca and Augustine. And when Rousseau subsequently, and even more spectacularly, proved unable to live up consistently to his own daunting standard of virtuous conduct, he was unafraid to draw one possible conclusion: “You want people always to be consistent”—the classical idea of rational unity. “I doubt that is possible for man; but what is possible for him is always to be true: that is what I mean to try to be.”