Born: 6th century BC
Heraclitus, a Greek philosopher of the late 6th century BC, lived in Ephesus, an important city on the Ionian coast of Asia Minor, not far from Miletus, the birthplace of philosophy.
We know nothing about his life other than what can be gleaned from his own statements, for all ancient biographies of him consist of nothing more than inferences or imaginary constructions based on his sayings.
For he criticizes by name important thinkers and writers with whom he disagrees, and he does not mention Parmenides.
On the other hand, Parmenides in his poem arguably echoes the words of Heraclitus. Heraclitus criticizes the mythographers Homer and Hesiod, as well as the philosophers Pythagoras and Xenophanes and the historian Hecataeus.
All of these figures flourished in the 6th century BCE or earlier, suggesting a date for Heraclitus in the late 6th century. Although he does not speak in detail of his political views in the extant fragments, Heraclitus seems to reflect an aristocratic disdain for the masses and favor the rule of a few wise men, for instance when he recommends that his fellow-citizens hang themselves because they have banished their most prominent leader.
Heraclitus criticizes his predecessors and contemporaries for their failure to see the unity in experience. He 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.
- "Character is destiny." (from "On the Universe")
- "All things come out of the one, and the one out of all things." (from "A History of Western Philosophy" by Bertrand Russell)
- "All men have the capacity of knowing themselves and acting with moderation." (from "Ancilla to Pre-Socratic Philosophers: A Complete Translation of the Fragments in Diels" by Fragmente der Vorsokratiker)
- "All things are in motion and nothing is at rest. ... You cannot go into the same [river] twice." (from "Cratylus", by Plato)
- "Eyes are more exact witnesses than ears." (from "From Thales to Plato", by T. V. Smith)
- "God is day and night, winter and summer, war and peace, satiety and hunger." (from "From Thales to Plato", by T. V. Smith)
- "War is father and king of all." (from "From Thales to Plato", by T. V. Smith)
- "All things come into being by conflict of opposites." (from "Lives of Eminent Philosophers", by Diogenes Laertius)
- "Much learning does not teach understanding." (from "Lives of Eminent Philosophers", by Diogenes Laertius)
- "Nothing endures but change." (from "Lives of Eminent Philosophers", by Diogenes Laertius)
- "The Lord whose oracle is at Delphi neither reveals nor conceals, but he indicates his meaning through hints." (from "The Open Society and Its Enemies", by Karl R. Popper)
- "Those who are awake have One common world." (from "The Open Society and Its Enemies", by Karl R. Popper)