Definition: Ataraxia is a Greek word that in ancient times referred to the belief that one's life was predetermined and could not be altered by human actions. It was a concept prevalent among ancient Greek philosophers, including Aristotle, who believed that individuals had no control over their own destiny or fate. The term "ataraxia" is often used figuratively to describe someone or something that has been given an inborn quality or nature that cannot be changed by any external force.