The history of economic thought deals with different thinkers and theories in the subject that became political economy and economics, from the ancient world to the present day. It encompasses many disparate schools of economic thought. Ancient Greek writers such as the philosopher Aristotle examined ideas about the art of wealth acquisition, and questioned whether property is best left in private or public hands. In medieval times, scholasticists such as Thomas Aquinas argued that it was a moral obligation of businesses to sell goods at a just price.