During Aristotle's time there was a shift in thought and a shift in belief, dealing directly with religion. Aristotle attended these issues in society. Aristotle was apart of a very strong social movement. Aristotle used an observational approach to help show examples of why these differences made better sense than the beliefs that existed before. .
During the time Aristotle was writing On the Heavens and his other works, the Greek people were beginning to question religion. They began to put their gods on trial. (Exploring Ancient World Cultures.).
The old gods that lived in the minds of the ancient Greeks had supernatural powers, but were limited by the concept of fate. Destiny hindered the power of the gods and because of this the gods were seen as fallible creatures. The gods simply were viewed as bigger than humans but not different or alien. They had faults like mankind in that they fought one another and often meddled in human affairs. (Exploring Ancient World Cultures.).
The intellectual city dwellers began to realize the gods did not answer with the visible and immediate rewards that were expected. Many people began adopting monotheistic beliefs, and gave the God Apollo many of the qualities that the other gods owned. Apollo eventually appropriated many of the virtues of the older gods, such as justice, harmony, legalism, and moderation. The tension between the Apollonian and Dionysian strains was particularly illustrated in the work of the tragic poets of Greece, who had begun to question the justice and integrity of the gods. (The Internet Encyclopedia of Philosophy.).
Once the gods were on trial the door was open for popular religion of the Greek countryside. No longer could the gods be trusted to make the Greek's short lives worthwhile, as the gods were not visible in everyday life. An emphasis on an after life, with a heaven and regeneration, returning to the earth as a different spirit, were introduced.