Before revision: Lewis H. Morgan Lewis H. Morgan, an anthropologist whose ideas have had much impact on sociology, in his 1877 classic Ancient Societies differentiated between three eras: savagery, barbarism and civilisation, which are divided by technological inventions, like fire, bow, pottery in savage era, domestication of animals, agriculture, metalworking in barbarian era and alphabet and writing in civilisation era with Morgan introducing further subdivisions into the first two stages.
After revision: Lewis H. Morgan In his 1877 classic Ancient Societies , lawyer and anthropologist Lewis H. Morgan followed Montestquieu and Tylor in distinguishing three eras: savagery, barbarism and civilisation, with Morgan introducing further subdivisions into the first two stages.