Covers the 19th century philosophers, including the basic writings of Kant, Fichte, Hegel, Schopenhauer, Comte, Mill, Spencer, Marx, Mach, Nietzsche, and Kierkegaard. Selections edited by, Introduction, and commentary by Henry D. Aiken, professor of Philosophy at Harvard at the time of publication.
In the 19th century the philosophies of the Enlightenment began to have a dramatic effect, the landmark works of philosophers such as Immanuel Kant and Jean-Jacques Rousseau influencing new generations of thinkers. In the late 18th century a movement known as Romanticism began; it validated strong emotion as an authentic not of aesthetic experience, placing new emphasis on such emotions as trepidation, horror and terror and awe.
Key ideas that sparked changes in philosophy were the fast progress of science; evolution, as postulated by Vanini, Diderot, Lord Monboddo, Erasmus Darwin, Lamarck, Goethe, and Charles Darwin; and what might now be called emergent order, such as the free market of Adam Smith within nation states. Pressures for egalitarianism, and more rapid change culminated in a period of revolution and turbulence that would see philosophy change as well.