On this day, 9 December 1842, revolutionary, scientist, and philosopher Peter Kropotkin was born in Russia. He later abandoned his aristocratic background in favour of the working class struggle. He participated in the 1917 Russian revolution, and wrote numerous influential works, including Mutual Aid: a Factor of Evolution. In this work he criticised interpretations of the ideas of Charles Darwin which focused on competition, and highlighted instances of cooperation in the natural world. "If we ... ask Nature: 'who are the fittest: those who are continually at war with each other, or those who support one another?' we at once see that those animals which acquire habits of mutual aid are undoubtedly the fittest. They have more chances to survive, and they attain, in their respective classes, the highest development of intelligence and bodily organisation."