It presents a scientific basis for communism as an alternative to the historical materialism of the Marxists. Kropotkin considers the importance of mutual aid for prosperity and survival in the animal kingdom, in indigenous and early European societies, in the Medieval free cities (especially through the guilds), and in the late 19th century village, labor movement, and poor folk. He criticizes the State for destroying historically important mutual aid institutions, particularly through the imposition of private property.