Joseph Horowitz writes in Moral Fire: "If the Met’s screaming Wagnerites standing on chairs (in the 1890s) are unthinkable today, it is partly because we mistrust high feeling. Our children avidly specialize in vicarious forms of electronic interpersonal diversion. Our laptops and televisions ensnare us in a surrogate world that shuns all but facile passions; only Jon Stewart and Bill Maher share moments of moral outrage disguised as comedy."

Arguing that the past can prove instructive and inspirational, Horowitz revisits four astonishing personalities—Henry Higginson, Laura Langford, Henry Krehbiel and Charles Ives—whose missionary work in the realm of culture signaled a belief in the fundamental decency of civilized human nature, in the universality of moral values, and in progress toward a kingdom of peace and love.