“Heraclitus, Empedocles, and Parmenides all state or suggest that thinking the right kinds of thoughts positively transforms our relationship to our environment. If thoughts are the right kind, it is presumably because they build on the particular receptivity of human nature to true knowledge about the nature of things, knowledge that, in turn, brings the person into greater harmony with the world around him. Thought is thus a uniquely transformative encounter with reality.”

“Xenophon tells us that Socrates never neglected the body and did not praise those who did. We can imagine that it was because the physical body—volatile, unseen, and implicated in an automatized natural world—could seem so daemonic that entrusting life, both biological life and ethical life, to its dynamics could seem like ceding control of the human.”

“Having a body, we have seen, does not entail knowing a body. Whereas a cow automatically eats whatever grasses supply needed nutrients, people must determine for themselves what to put into their bodies, with the result that there is room to make mistakes. Mistakes arise, in part, from ignorance. Yet ignorance is not the only problem produced by this arrangement. The fact that we are not compelled by our bodies' precise needs—understood as particular kinds of food and drink, rather than food and drink tout court—allows the formation of desires that have little or nothing to do with the needs on which bodily health depends.”

“Heraclitus, Empedocles, and Parmenides all state or suggest that thinking the right kinds of thoughts positively transforms our relationship to our environment. If thoughts are the right kind, it is presumably because they build on the particular receptivity of human nature to true knowledge about the nature of things, knowledge that, in turn, brings the person into greater harmony with the world around him. Thought is thus a uniquely transformative encounter with reality.”