A Factor of EvolutionMutual Aid: A Factor of Evolution Peter Kropotkin 1902 Chapter 1: MUTUAL AID AMONG ANIMALS Struggle for existence. -- Mutual Aid -- a law of Nature and chief factor of progressive evolution. -- Invertebrates. -- Ants and Bees -- Birds: Hunting and fishing associations. -- Sociability. -- Mutual protection among small birds. -- Cranes; parrots. The conception of struggle for existence as a factor of evolution, introduced into science by Darwin and Wallace, has permitted us to embrace an immensely wide range of phenomena in one single generalization, which soon became the very basis of our philosophical, biological, and sociological speculations. An immense variety of facts: -- adaptations of function and structure of organic beings to their surroundings; physiological and anatomical evolution; intellectual progress, and moral development itself, which we formerly used to explain by so many different causes, were embodied by...