Ancient Greek philosophy arose in the 6th century BC and continued throughout the Hellenistic（希腊文化的） period and the period in which Ancient Greece was part of the Roman Empire.
Philosophy was used to make sense out of the world in a non-religious way. It dealt with a wide variety of subjects, including political philosophy, ethics, metaphysics（形而上学）, ontology（存在论）, logic, biology, rhetoric（修辞学） and aesthetics. （From Wikipedia）
Many philosophers around the world agree that Greek philosophy has influenced much of Western culture since its inception.