During the period from 477 to 431 BC, Athens experienced a cultural and intellectual golden age under the leadership of Pericles. Pericles strengthened Athenian democracy and used the wealth of the Athenian Empire to fund magnificent architecture projects, such as the Parthenon. However, the Peloponnesian War between Athens and Sparta from 431 to 404 BC weakened Athens and ended the Golden Age. After the war, Athenian philosophers like Socrates, Plato, and Aristotle sought philosophical truths through logic and reason.