The author, a philosopher, uses the language of philosophy with concise clarity. He demonstrates how closely certain ideas of Spinoza and Kant came to ideas that Freud later developed. These include determinism and its bearing on the idea of free will, the pleasure and reality principles, and the superego. The author finds the idea of a death instinct particularly attractive and extends this idea far beyond the biological with a certainty that is amazing considering how controversial it is. He concludes that the death instinct deals a death blow to all interpretations of Freud which emphasize his contributions to sex knowledge.