"There is an immense amount of warfare and extermination going on amidst various species; there is, at the same time, as much, or perhaps even more, of mutual support, mutual aid, and mutual defense... Sociability is as much a law of nature as mutual struggle." As a description of biology, Kropotkin's perspective is consistent with contemporary understanding. Stephen Jay Gould admired Kropotkin's observations, noting that cooperation, if it increases individual survival, is not ruled out by natural selection, and is in fact encouraged. Kropotkin's ideas anticipate the now recognized importance of mutualism (a beneficial relationship between two different species) and altruism (when one member of a species aids another) in biology. Examples of altruism in animals include kin selection and reciprocal altruism. Douglas H. Boucher places Kropotkin's book as a precursor to the development of the biological theory of altruism. Editions Includes Kropotkin's 1914 preface, Foreword and Bibliography by Ashley Montagu, and The Struggle for Existence, by Thomas H. Huxley See also A Darwinian Left: Politics, Evolution and Cooperation Ethology Evolutionary anthropology Psychological egoism List of books about anarchism References External links Mutual Aid: A Factor of Evolution at The Anarchist Library Mutual Aid: A Factor of Evolution at Libcom.org Mutual Aid: A Factor of Evolution – HTML version at the Anarchy Archives Mutual Aid: A Factor of Evolution – Plain PDF version at the RevoltLib Paul Mattick, Kropotkin on Mutual Aid — Review, 1956. Iain McKay, Mutual Aid: An Introduction and Evaluation, AK Press, Edinburgh, 2010. Works by Peter Kropotkin 1902 non-fiction books Books about evolution Heinemann (publisher) books Mutualism (biology) Philosophy books Works originally published in Nineteenth Century (periodical)