The final volume of Singer's trilogy discusses ideas about love in the work of writers ranging from Kierkegaard, Nietzsche, and Tolstoy to Freud, Proust, D. H. Lawrence, Shaw, and others in the contemporary world.

Irving Singer's trilogy The Nature of Love has been called "majestic" (New York Times Book Review), "monumental" (Boston Globe), "one of the major works of philosophy in our century" (Nous), "wise and magisterial" (Times Literary Supplement), and a "masterpiece of critical thinking [that] is a timely, eloquent, and scrupulous account of what, after all, still makes the world go round" (Christian Science Monitor).

In the third volume, Singer examines the pervasive dialectic between optimistic idealism and pessimistic realism in modern thinking about the nature of love. He begins by discussing "anti-Romantic Romantics" (focusing on Kierkegaard, Nietzsche, and Tolstoy), influential nineteenth-century thinkers whose views illustrate much of the ambiguity and self-contradiction that permeate thinking about love in the last hundred years. He offers detailed studies of Freud, Proust, Shaw, D. H. Lawrence, and Santayana, and he maps the ideas about love in Continental existentialism, particularly those of Sartre and de Beauvoir. Singer finally envisages a future of cooperation between pluralistic humanists and empirical scientists. This last volume of Singer's trilogy does not pretend to offer the final word on the subject, any more than do most of the philosophers he discusses, but his masterful work can take its place beside their earlier investigations into these vast and complex questions.