- "Pre-Socratic philosophy, also known as Early Greek Philosophy, is ancient Greek philosophy before Socrates." - Pre-Socratic philosophy: "Pre-Socratic philosophy, also known as Early Greek Philosophy, is ancient Greek philosophy before Socrates."
It includes the philosophical works of ancient Greek thinkers like Thales, Anaximander, Heraclitus, and others before the time of Socrates.
- "Pre-Socratic philosophers were mostly interested in cosmology, the beginning and the substance of the universe, but the inquiries of these early philosophers spanned the workings of the natural world as well as human society, ethics, and religion."
- "They sought explanations based on natural law rather than the actions of gods."
- "Their work and writing has been almost entirely lost."
- "Knowledge of their views comes from testimonia, i.e. later authors' discussions of the work of pre-Socratics."
- "Philosophy found fertile ground in the ancient Greek world because of the close ties with neighboring civilizations and the rise of autonomous civil entities, poleis."
- "Pre-Socratic philosophy began in the 6th century BCE with the three Milesians: Thales, Anaximander, and Anaximenes. They all attributed the arche of the world to, respectively, water, apeiron (the unlimited), and air."
- "Xenophanes is known for his critique of the anthropomorphism of gods."
- "Heraclitus, who was notoriously difficult to understand, is known for his maxim on impermanence, ta panta rhei."
- "Pythagoras created a cult-like following that advocated that the universe was made up of numbers."
- "The Eleatic school (Parmenides, Zeno of Elea, and Melissus) followed in the 5th century BCE."
- "Parmenides claimed that only one thing exists and nothing can change."
- "Zeno and Melissus mainly defended Parmenides' opinion."
- "Anaxagoras and Empedocles offered a pluralistic account of how the universe was created."
- "Leucippus and Democritus are known for their atomism, and their views that only void and matter exist."
- "The Sophists advanced philosophical relativism."
- "The pre-Socratics invented some of the central concepts of Western civilization, such as naturalism and rationalism."
- "...and paved the way for scientific methodology."
- "Another three pre-Socratic philosophers came from nearby Ionian towns: Xenophanes, Heraclitus, and Pythagoras."
- "Pre-Socratic philosophy began in the 6th century BCE with the three Milesians: Thales, Anaximander, and Anaximenes."