Atheism is the belief that there is no God or gods and that whatever happens in the world is due to natural causes, not divine intervention. The history of atheism is actually longer than many people realize. In ancient times, some Greeks were skeptical of traditional religion and suggested rational explanations for natural phenomena. In some cultures, like those in India, questions about the existence of gods were openly discussed. During the Middle Ages, however, atheism was widely persecuted, as it presented a challenge to the established religious authorities. In the Renaissance, questions were once again given free reign to be explored, and many prominent thinkers began to challenge the assumption that religion was necessary in order to explain the world. As science developed and religion became less politically dominant, more people began to explore their own beliefs and some chose to reject the existence of a higher power altogether. In the 19th and 20th centuries, these ideas were developed further and atheism took on a more vocal presence in society. Atheism today is more widely accepted than it's ever been, and there are many people who use science and rationality as a basis for living that don't believe in any type of higher power.