Impiety is a perceived lack of proper respect for something considered sacred. Impiety is often closely associated with sacrilege, though it is not necessarily a physical action. Impiety cannot be associated with a cult, as it implies a larger belief system was disrespected. One of the Pagan objections to Christianity was that, unlike other mystery religions, early Christians refused to cast a pinch of incense before the images of the gods, an impious act in their eyes. Impiety in ancient civilizations was a civic concern, rather than religious. It was believed that impious actions such as disrespect towards sacred objects or priests could bring down the wrath of the gods. Impiety was often used to prosecute atheists, who were widely discriminated against.
Anaxagoras, an Athenian scholar, proposed that the sun and the stars were fiery stones whose heat we did not feel because of their distance. Athena used this to justify a charge of impiety and forced Anaxagoras into exile. Diagoras of Melos was accused of atheism, and had to flee Athens after being charged with impiety for revealing the Eleusinian mysteries and allegedly chopping up a statue of Heracles for firewood. Aristotle, mentor to Alexander the Great, was almost charged with impiety for refusal to recognize the divinity of his pupil and not holding the gods in honor. Aristotle fled the city before a trial could take place, saying, "I will not allow the Athenians to sin twice against philosophy".