Brooks opens with a brief description of those who “radiate joy” (xi). Such people, who have deeply held commitments to others and who feel delight in vocational dedication to these commitments are an inspiration for The Second Mountain. According to Brooks, these joyful people have often led a life with a “two-mountain shape” (xi). The concept of the second mountain and the person who climbs to its metaphorical peak structures the entire book; it is the book’s primary concept.

Brooks writes that on the first mountain a person is busy becoming an individual, creating and building an ego through independent realization of personal goals. Continuing the metaphor, Brooks writes that between the first and second mountains is a valley. The valley is a “season of suffering” in which some people are radically transformed (xiii). These people learn, through their struggles in this period of suffering, that they are more than the ego-identity they’ve created for themselves: “There is another layer of them they have been neglecting, a substrate where the dark wounds, and the most powerful yearnings live” (xii). While some people fall to pieces in the valley, others find themselves and begin their assent up the second mountain.