From the seventeenth century onwards, numerous European movements of enlightenment made the consciousness of human freedom not only the measure of thought, but also the foundation of politics. This introduction to rationalism, empiricism and political philosophy impressively demonstrates the inseparability of thought and action as the central idea of the intellectual awakening. Central figures discussed are Descartes, Hobbes, Spinoza, Locke, Leibniz, Hume and Rousseau.