"πάντα ῥεῖ (panta rhei) - everything flows"

Heraclitus of Ephesos

Heraclitus was a pre-Socratic Greek philosopher born in the city of Ephesus c. 535 BC (died c. 475 BC). Little is known about his early life and education, but we know that he was of distinguished parentage, and he regarded himself as self-taught and a pioneer of wisdom. He was called “The Obscure” and the “Weeping Philosopher” because of the lonely life he led and also because of the riddled and allegedly paradoxical nature of his philosophy.

Heraclitus was famous for his insistence on ever-present change as being the fundamental essence of the universe, as stated in the famous saying, “No man ever steps in the same river twice”. This is commonly considered to be a key contributor in the development of the philosophical concept of becoming, as contrasted with “being”, and has sometimes been seen in a dialectical relationship with Parmenides’ statement that “whatever is, is, and what is not cannot be”, the latter being understood as a key contributor in the development of the philosophical concept of being. For this reason, Parmenides and Heraclitus are commonly considered to be two of the founders of ontology. Heraclitus’ position was complemented by his stark commitment to a unity of opposites in the world, stating that “the path up and down is one and the same”. Heraclitus characterized all existing entities by pairs of contrary properties, whereby no entity may ever occupy a single state at a single time.

What is Heraclitus known for?

Heraclitus claim to philosophical fame is his position that all things are one, in some sense. According to Heraclitus, the world itself consists of interchange of elements, symbolized by fire. So the world is not to be identified as an ongoing process governed by a law of change. Heraclitus is the first Western philosopher to go beyond physical theory in search of metaphysical foundations and moral applications.

Theory of Knowledge

Heraclitus sees the great majority of human beings as lacking understanding. According to Heraclitus, most people sleep-walk through life, not understanding what is going on about them. Yet the experience of words and deeds can enlighten those who are receptive to their meaning.

The Doctrine of Flux and the Unity of Opposites

Plato and Aristotle thought that Heraclitus held extreme views that led to logical incoherence. On one hand, he believed that everything is constantly changing and opposite things are identical so that everything is and is not at the same time. In other words, Universal Flux and the Identity of Opposites entail a denial of the Law of Non-Contradiction. Plato indicates the source of the flux doctrine: “Heraclitus, I believe, says that all things go and nothing stays and comparing existents to the flow of a river, he says you could not step twice into the same river” (Cratylus 402a).

What Heraclitus actually says is the following: On those stepping into rivers staying the same other and other waters flow.

Physical Theory

Heraclitus’ criticisms and metaphysical speculations are grounded in a physical theory. He expresses the principles of his cosmology in a single sentence:

This world-order, the same of all, no god nor man did create, but it ever was and is and will be: everliving fire, kindling in measures and being quenched in measures.

This passage contains the earliest philosophical use of the word kosmos, “world-order,” denoting the organized world in which we live, with earth, sea, atmosphere, and heavens. For Heraclitus, flux and opposition are necessary for life.

Accomplishments and Influence

Heraclitus goes beyond the natural philosophy of the other Ionian philosophers to make profound criticisms and develop far-reaching implications of those criticisms.

Influenced by the teachings of the Heraclitean Cratylus, Plato saw the sensible world as exemplifying flux. Plato and Aristotle both criticized Heraclitus for a radical theory that led to a denial of the Law of Non-Contradiction. The Stoics adopted Heraclitus’s physical principles as the basis for their theories.

Further reading (external links):