"πάντα ῥεῖ (panta rhei) - everything flows"

Heraclitus of Ephesos

Heraclitus of Ephesus (c. 535 – c. 475 BC) was a pre-Socratic Greek philosopher and a native of the city of Ephesus. He was of distinguished parentage. Little is known about his early life and education, but he regarded himself as self-taught and a pioneer of wisdom. From the lonely life he led, and still more from the apparently riddled and allegedly paradoxical nature of his philosophy and his stress upon the heedless unconsciousness of humankind, he was called “The Obscure” and the “Weeping Philosopher”.

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 contribution 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 contribution 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. Scholars have generally believed that either Parmenides was responding to Heraclitus, or Heraclitus to Parmenides, though opinion on who was responding to whom has varied over the course of the 20th and 21st centuries. 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”. Through these doctrines, Heraclitus characterized all existing entities by pairs of contrary properties, whereby no entity may ever occupy a single state at a single time. This, along with his cryptic utterance that “all entities come to be in accordance with this Logos” (literally, “word”, “reason”, or “account”) has been the subject of numerous interpretations.

What is Heraclitus known for?

Heraclitus claims to announce an everlasting Word (Logos) according to which all things are one, in some sense. Opposites are necessary for life, but they are unified in a system of balanced exchanges. The world itself consists of a law-like interchange of elements, symbolized by fire. Thus the world is not to be identified with any particular substance, but rather with an ongoing process governed by a law of change. The underlying law of nature also manifests itself as a moral law for human beings. 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:

Of this Word’s being forever do men prove to be uncomprehending, both before they hear and once they have heard it. For although all things happen according to this Word they are like the unexperienced experiencing words and deeds such as I explain when I distinguish each thing according to its nature and declare how it is. Other men are unaware of what they do when they are awake just as they are forgetful of what they do when they are asleep. 

Most people sleep-walk through life, not understanding what is going on about them. Yet experience of words and deeds can enlighten those who are receptive to their meaning.

The Doctrine of Flux and the Unity of Opposites

According to both Plato and Aristotle, Heraclitus held extreme views that led to logical incoherence. For he held 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.

There is an antithesis between ‘same’ and ‘other.’ The sentence says that different waters flow in rivers staying the same. In other words, though the waters are always changing, the rivers stay the same. Indeed, it must be precisely because the waters are always changing that there are rivers at all, rather than lakes or ponds. The message is that rivers can stay the same over time even though, or indeed because, the waters change. The point, then, is not that everything is changing, but that the fact that some things change makes possible the continued existence of other things. Perhaps more generally, the change in elements or constituents supports the constancy of higher-level structures.

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 extant 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. Aristotle reports,

Heraclitus criticizes the poet who said, ‘would that strife might perish from among gods and men’ [Homer Iliad 18.107]’ for there would not be harmony without high and low notes, nor living things without female and male, which are opposites.

For Heraclitus fire changes into water and then into earth; earth changes into water and then into fire. At the level of either cosmic bodies (in which sea turns into fiery storms on the one hand and earth on the other) or domestic activities (in which, for instance, water boils out of a pot), there is constant flux among opposites. To maintain the balance of the world, we must posit an equal and opposite reaction to every change. Heraclitus observes, The road up and down is one and the same”.

Here again, we find a unity of opposites, but no contradiction. One road is used to pursue two different routes. Daily traffic carries some travelers out of the city, while it brings some back in. The image applies equally to physical theory: as earth changes to fire, fire changes to earth. And it may apply to psychology and other domains as well.

Moral and Political Theory

There has been some debate as to whether Heraclitus is chiefly a philosopher of nature (a view championed by G. S. Kirk) or a philosopher concerned with the human condition (C. H. Kahn). The opening words of Heraclitus’ book seem to indicate that he will expound the nature of things in a way that will have profound implications for human life. In other words, he seems to see the theory of nature and the human condition as intimately connected. In fact, recently discovered papyri have shown that Heraclitus is concerned with technical questions of astronomy, not only with general theory. There is no reason, then, to think of him as solely a humanist or moral philosopher. On the other hand, it would be wrong to think of him as a straightforward natural philosopher in the manner of other Ionian philosophers, for he is deeply concerned with the moral implications of physical theory.

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. He suggests the first metaphysical foundation for philosophical speculation, anticipating process philosophy. And he makes human values a central concern of philosophy for the first time. His aphoristic manner of expression and his manner of propounding general truths through concrete examples remained unique.

Heraclitus’s paradoxical exposition may have spurred Parmenides’ rejection of Ionian philosophy. Empedocles and some medical writers echoed Heraclitean themes of alteration and ongoing process, while Democritus imitated his ethical observations. Influenced by the teachings of the Heraclitean Cratylus, Plato saw the sensible world as exemplifying a Heraclitean 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.

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