At the very time that industrialists, inventors, statesmen, and natural scientists were conquering new objective worlds, Gay writes, "the secret life of the self had grown into a favorite and wholly serious indoor sport."

Following the middle class's preoccupation with inwardness through its varied cultural expressions (such as fiction, art, history, and autobiography), Gay turns also to the letters and confessional diaries of both obscure and prominent men and women. These revealing documents help to round out a sparkling portrait of an age.