The book discusses Bacon, Descartes, Bayle, Fontenelle, Hobbes, Locke, Berkeley, Hume, Voltaire, Rousseau, Diderot, d'Alembert, La Mettrie, Holbach, Kant, Schiller and many other philosophers. These philosophers were united in their belief that reason rather than revelation is the primary source of authority and they courageously attempted to destroy traditional, superstitious and religious ideas and replace them with a liberal, rational and humane worldview. This books is a declaration of respect and admiration for these philosophers.