Lewis Henry Morgan
Ancient society : $b or, Researches in the lines of human progress from savagery, through barbarism to civilization
"Ancient Society: or, Researches in the lines of human progress from savagery" by Lewis H. Morgan is an anthropological work published in 1877. Building on his earlier kinship research, Morgan proposes that human societies progress through three universal stages: Savagery, Barbarism, and Civilization. He develops this theory by comparing what he calls "ethna"—inventions, discoveries, and institutions—across different cultures. His ideas profoundly influenced European thinkers including Marx and Engels, shaping debates about social evolution and human development that continue to resonate in anthropology today.