Darwin’s publication of On the Origin of Species sparked major battles. The most famous may have been between science and religion, but there were disputes within science as well. One of the most heated was whether natural selection favored cooperative or competitive behaviors, a battle that still rages today. For almost 100 years, no single person did more to promote the study of the evolution of cooperation than Peter Kropotkin.

Kropotkin traveled the world talking about the evolution of cooperation, which he called “mutual aid,” in both animals and humans. Sometime the travel was voluntary, but often it wasn’t: He was jailed, banned, or expelled from many of the most respectable countries of his day. For he was not only the face of the science of cooperation, he was also the face of the anarchist movement. He came to believe that his politics and science were united by the law of mutual aid: that cooperation was the predominant evolutionary force driving all social life, from microbes to humans.

Read more at Slate.