This essay historically explores philosophical views about the nature and significance of human sexuality, starting with the Ancient Greeks and ending with late 20th-century Western philosophy. Important figures from the history of philosophy (and theology) discussed include Sappho, Plato, Aristotle, St. Augustine, St. Jerome, the Pelagians, St. Thomas Aquinas, Michel de Montaigne, Rene Descartes, Thomas Hobbes, David Hume, Immanuel Kant, Søren Kierkegaard, Arthur Schopenhauer, Jeremy Bentham, John Stuart Mill, Karl Marx, Friedrich Engels, Sigmund Freud, Jean-Paul Sartre, Simone de Beauvoir, Wilhelm Reich, and Herbert Marcuse. Contemporary philosophers whose recent work is discussed include Michel Foucault, Thomas Nagel, Roger Scruton, Karol Wojtyla (Pope John Paul II), Catharine MacKinnon, Richard Posner, and John Finnis. To show the unity of the humanities, the writings of various literary figures are incorporated into this history, including Mark Twain, Arthur Miller, James Thurber, E. B. White, Iris Murdoch, and Philip Roth.