In the 19th century, the philosophers of the 18th-century Enlightenment began to have a dramatic effect on subsequent developments in philosophy. In particular, the works of Immanuel Kant gave rise to a new generation of German philosophers and began to see wider recognition internationally. Also, in a reaction to the Enlightenment, a movement called Romanticism began to develop towards the end of the 18th century. Key ideas that sparked changes in philosophy were the fast progress of science, including evolution, most notably postulated by Charles Darwin and Jean-Baptiste Lamarck, and theories regarding what is today 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.
"Social Darwinism" refers to theories that apply the evolutionary concept of natural selection to human society.