Principles of Ancient Greek & Roman Philosophy
- All philosophers discussed the nature and purpose of the universe; science, religion and philosophy were closely linked during this time period. Democritus correctly guessed that small particles he called "atoms" composed the universe, but most philosophers held incorrect beliefs about the Earth's shape, its location in the universe and the nature of matter. Nevertheless, fields including astronomy and mathematics grew out of these discussions.
- How humans should act was a question equally important to ancient philosophers. The dialogues of Plato and Aristotle, whose original published writings no longer exist, asked questions about justice, morality and the consequences of human actions. Almost no philosophers believed that life has no purpose, but sometimes they claimed that its only purpose was personal pleasure.
- Ancient philosophers argued about the nature of the mind and the soul, as well as where language comes from. These discussions gave birth to rhetoric, logic and reasoning. While most philosophers believed that humans have an eternal essence, some thought discussing the afterlife was pointless. For example, the Roman emperor-philosopher Marcus Aurelius believed that acting reasonably should be a human's only concern. Reasoning and the power of the mind were the ancient philosophers' highest values.
- Ancient philosophers also debated political issues, such as which type of government worked best and who should be in charge. Though closely related to ethics and other philosophical issues, politics was important in its own right because governments did not grant citizenship easily in the ancient world, and voting as a union instead of submitting to rule was a relatively new idea.