In the first half of the book Professor Santas reconstructs and explains Plato's theories of eros and philia: erotic love, familial love and friendship. He attempt to show that Plato's was a unified theory in which erotic love has a special connecion with creativity and beauty. He then discusses Freud's notion of love as distinct from, though based on, his general theory of sexuality. He discusses in detail Freud's explanations, before and after narcissism, of idealization and choice of beloved. Freud too, it emerges, had a unified theory of love: all love has its origins in the libidinal instincts of infancy and childhood.

The book concludes by showing that, despite Freud's claim that his theory of love is 'Platonic', the two theories are instructively different.