The era of German Idealism stands alongside ancient Greece and the French Enlightenment as one of the most fruitful and influential periods in the history of philosophy. The names and ideas of the great innovators continue to resonate with us, to inform our thinking and spark debates of interpretation: Socrates, Plato, and Aristotle; Voltaire and Rousseau; Kant and Hegel. Beginning with the publication of Kant's Critique of Pure Reason in 1781 and ending about ten years after Hegel's death in 1831, the period of "classical German philosophy" transformed whole fields of intellectual endeavor and founded others. The German Idealists blurred the distinction between epistemology and metaphysics, showing that the study of nature is impossible without investigating the subjective conditions for the possibility of experience. Their conception of autonomy as rational self-legislation challenged thousands of years of ethical theory and supported political and educational theories that both extended and qualified the ideals of the Enlightenment. In aesthetics, their focus on the formal qualities of the art object and the sensibility of the viewer established new traditions of art interpretation that have influenced artists and critics of their own time and ours. And they set limits to religious faith, supporting religion only insofar as it makes manifest and reinforces the ethical commitments that we can discover through rational reflection and exemplify in community with others.