Essays on the revolutionary Russian anarchist's ideas about mutual aid, sex, and participatory democracy for the twenty-first century. Prince Peter Kropotkin (1842-1921) was one of the great thinkers of the late nineteenth and early twentieth centuries. As a Russian anarchist, philosopher, economist, historian, geographer, and scientist, Kropotkin had a range of contributions that were as divergent as they were holistic. Kropotkin's critical thought on issues such as mutual aid and anarchism have become tenets of multiple twenty-first-century social movements. As the foundations of neoliberalism shake and neofascist movements spawn around the world, the practice of mutual aid, the theories of anarchism and participatory democracy, and critique of social Darwinism have seldom been as important as they are today. Many activists and scholars are using Kropotkin's ideas to challenge these authoritarian threats and to work toward an egalitarian future. Kropotkin Now! is the culmination of an international effort to investigate Kropotkin's ideas and to imagine new alternatives on the centenary of his death. Contributors engage Kropotkin's work in diverse contexts, including evolution and mutual aid, cyborgs and feminist technoscience, Kropotkin's treatment of "the sex question," urbanization, building dual power, and more.