When we’re aspiring, inarticulateness isn’t a sign of unreasonableness or incapacity. In fact, the opposite may be true. “Everyone goes to college ‘to become educated,’ ” Callard observes, “but until I am educated I do not really know what an education is or why it is important.” If we couldn’t aspire to changes that we struggle to describe, we’d be trapped within the ideas that we already have. Our inability to explain our reasons is a measure of how far we wish to travel. It’s only after an aspirant has reached her destination, Callard writes, that “she will say, ‘This was why.’ ”

We say that we “decide” to get married, to have children, to live in particular cities or embark on particular careers, and in a sense this is true. But how do we actually make those choices? One of the paradoxes of life is that our big decisions are often less calculated than our small ones are. We agonize over what to stream on Netflix, then let TV shows persuade us to move to New York; buying a new laptop may involve weeks of Internet research, but the deliberations behind a life-changing breakup could consist of a few bottles of wine. We’re hardly more advanced than the ancient Persians, who, Herodotus says, made big decisions by discussing them twice: once while drunk, once while sober.