Most important, she notes that the quality of our longing matters. Gritty people are resilient and hard working, sure. But they also, she writes, know in a very, very deep way what it is they want.

This is a crucial leap. It leads to a very different set of questions and approaches. How do we help students decide what they want? How do we improve the quality and ardor of their longing?

The G.P.A. mentality is based on the supposition that we are thinking creatures. Young minds have to be taught self-discipline so they can acquire knowledge. That’s partly true, but as James K. A. Smith notes in his own book “You Are What You Love,” human beings are primarily defined by what we desire, not what we know. Our wants are at the core of our identity, the wellspring whence our actions flow.

At the highest level, our lives are directed toward some telos, or vision of the good life. Whether we are aware of it or not, we’re all oriented around some set of goals. As David Foster Wallace put it in his Kenyon commencement address, “In the day-to-day trenches of adult life, there is actually no such thing as atheism. There is no such thing as not worshiping. Everybody worships.” Some worship money, or power or popularity or nursing or art, but everybody’s life is organized around some longing. The heart is both a driving engine and a compass.

I don’t know about you, but I’m really bad at being self-disciplined about things I don’t care about. For me, and I suspect for many, hard work and resilience can only happen when there is a strong desire. Grit is thus downstream from longing. People need a powerful why if they are going to be able to endure any how.

Duckworth herself has a very clear telos. As she defines it, “Use psychological science to help kids thrive.” Throughout her book, you can feel her passion for her field and see how gritty she has been in pursuing her end.

Suppose you were designing a school to help students find their own clear end — as clear as that one. Say you were designing a school to elevate and intensify longings. Wouldn’t you want to provide examples of people who have intense longings? Wouldn’t you want to encourage students to be obsessive about worthy things? Wouldn’t you discuss which loves are higher than others and practices that habituate them toward those desires? Wouldn’t you be all about providing students with new subjects to love?

In such a school you might even de-emphasize the G.P.A. mentality, which puts a tether on passionate interests and substitutes other people’s longings for the student’s own.