Query: In what work did Ferguson explain how humans advanced from a hunting and gathering society to a commercial and civil society without "signing" a social contract?
Context: Similarly, Ferguson did not believe citizens built the state, rather polities grew out of social development. In his 1767 An Essay on the History of Civil Society, Ferguson uses the four stages of progress, a theory that was very popular in Scotland at the time, to explain how humans advance from a hunting and gathering society to a commercial and civil society without "signing" a social contract.