The central question in ancient Greek thought is: "What is the origin of all things?" This origin is also referred to as arche. For example, Thales considered arche to be water.
| Philosopher | Arche |
|---|---|
| Thales | Water |
| Anaximenes | Air |
| Anaximander | Apeiron (the indefinite or boundless) |
| Democritus | Atoms |
| Heraclitus | Fire |
| Empedocles | Four elements (fire, water, earth, air) |
| Anaxagoras | Seeds and mind (nous) |
| Pythagoras | Numbers |
Milesian School
The three philosophers (Thales, Anaximenes, Anaximander) are known as the Milesian School. Miletus was a city located in Ionia.
Thales is also known as a scholar who predicted a solar eclipse and measured the height of the pyramids. He is called the father of natural philosophy.
Democritus
Democritus believed that atoms (indivisible particles) move through the void, a space of nothingness. This idea closely resembles the modern concept of atoms in chemistry.
Heraclitus
Heraclitus is famous for the phrase “everything flows” (panta rhei). What’s interesting is that while he claimed that all things are in constant flux, he also asserted that the origin of all things is fire.
Empedocles
Unlike other thinkers, Empedocles proposed that four substances (fire, water, earth, and air) are the fundamental elements.
This idea can be compared to the Five Elements theory (Wu Xing) of ancient China, which considers wood, fire, earth, metal, and water as the basic elements of the natural world.
The Development after Democritus and Epicurus
Democritus’ atomic theory was inherited by Epicurus, a philosopher known for his ideas on ataraxia (peace of mind) and hedonism (the pursuit of pleasure).
Epicurus believed that humans are merely collections of atoms, and that at death, these atoms simply disperse—therefore, there is no need to fear death.
