Observation or experience rather than theory or pure logic.
Division of labor led to complex civilization, surplus of food, and domestication of plants and animals.
Answer:
Battle of Lexington and Concord
Spartan society operated on a system of mass enslavement. The peoples of Messenia were enslaved as helots, and worked Spartan land so the citizens spartiates could , in accordance with the rules of the mythical Lycurgus , be fulltime professional soldiers. As this went on, a series of revolts made the Spartans relise that to keep the helots pacified , Sparta would need to continue its tradition of training all young men to the point of military excellence
