The document discusses early Greek philosophy from the 6th century BC to the 5th century AD. It outlines the major historical periods and thinkers of ancient Greece, including the Pre-Socratic philosophers like Thales, Anaximander, and Parmenides who sought to explain the natural world without recourse to mythology. It also discusses the Sophists who emphasized rhetoric and relativism, and the questions that occupied early Greek philosophers like the nature of reality and the ultimate substance of the cosmos.