The focus of the book is those aspects of the history of ideas which have something to say to our present preoccupations. After expounding the ideas of a particular thinker there follows a discussion of the material and how it relates to issues that are still alive today (indented from the margin and set in a different typeface), based on the author's classroom debates with his own students.
Another feature of the book is the many footnotes which refer the reader back to earlier, and forward to later, pages of the book. They are intended to reinforce the idea that throughout the centuries philosophers have often grappled with the same problems, sometimes coming up with similar approaches and sometimes with radically different ones.
Keywords: Philosophy, society, God, religion, ethics, morality, history of ideas, theology, politics, ideology, cosmology, Pythagoras, Protagoras, Sophists, Socrates, Plato, Aristotle, Cynicism, scepticism, skepticism, stoicism, Cicero, Seneca, Judaism, Christianity, Hellenism, neo-platonism, Philo, Origen, Plotinus, Porphyry, gnosticism, St Augustine, realism, nominalism, averroism, Aquinas, Roger Bacon, William of Ockham, Church, Renaissance, humanism, Petrarch, Machiavelli, the Reformation, Wyciffe, Hus, Luther, Calvin, Althusius, Bodin, scientific revolution, astronomy, Bruno, Francis Bacon, Descartes, Hobbes, epistemology, Pascal, Spinoza, Leibniz, Locke, political thought, Pragmatism, Berkeley, Hume, the Enlightenment, Bayle, De Fontereille, Newton, Helvetius, Voltaire, Holbach, Romanticism, Rousseau, Burke, Montesquieu, Vico, Condorcet, Herder, Kant, Fichte, Schelling, Hegel, Schopenhauer, Kierkegaard, utilitiarianism, Bentham, Mill, T.H. Green, Comte, Darwin, Spencer, Marx, Nietzsche, Bergson, existenitalism, Buber, Husserl, Heidegger, Sartre, pragmatism, Peirce, James, Dewey, Moore, Russell, Wittgenstein, logical positivism, Popper, Kuhn, Berlin, Freud, Jung, structuralism, post-structuralism, Saussure, Chomsky, Levi-Strauss, Braudel, Foucault