Heraclitus of Ephesus was an Ancient Greekpre-SocraticIonian philosopher and a native of the city of Ephesus, which was then part of the Persian Empire.

His appreciation for wordplay and oracular expressions, as well as paradoxical elements in his philosophy, earned him the epithet "The Obscure" from antiquity. He wrote a single work, On Nature, only fragments of which have survived, increasing the obscurity associated with his life and philosophy. Heraclitus's cryptic utterances have been the subject of numerous interpretations. He has been seen as a "material monist or a process philosopher; a scientific cosmologist, a metaphysician and a religious thinker; an empiricist, a rationalist, a mystic; a conventional thinker and a revolutionary; a developer of logic—one who denied the law of non-contradiction; the first genuine philosopher and an anti-intellectual obscurantist. (Adding Standford and Wikipedia content into further reading is done)


Arche is Flux

Heraclitus, too, says that the principle is the soul if indeed it is the exhalation from which he constructs the other things. And he says that it is the most incorporeal thing and is always flowing and that what is in motion is known by what is in movement. And he, along with many, believed that existing things depend on movement. (Aristotle - On the soul p.7 405a 35)

Hot things become cold, the cold becomes hot, wet becomes dry, parched become moist’ (frag. 126 Generation and Corruption) 

Unity of opposites

Perish all strife ‘ twist gods and twist men. There would be no harmony, he says, if there were not high and low notes, and there would be no animals without the contrary between males and females. (Aristotle - The Eudemian Ethics p. 113) 

It is harder to fight against pleasure than anger. (Aristotle - The Nicomachean Ethics p27 1105a  8) 

‘ t is what opposes that helps’ and ‘ From different tones comes the fairest tune’ and ‘ all things are produced through strife ‘.   (Aristotle - The Nicomachean Ethics p143 1155b 4) 


It is likely that Heraclitus has the strength of temper in mind when he says that keeping it in check is painful. ‘ It’s hard, he says, ‘ to fight with temper: it will gain victory at the cost of life.’ )(Aristotle - The Eudemian Ethics p. 26 1223b 22) 


Strength of opinion (Aristotle - The Nicomachean Ethics p122 1146b 31) 


Animals have different pleasures ‘ asses would prefer sweepings to gold’  (Aristotle - The Nicomachean Ethics p191 1176a 6) 


Some believe that the smoky exhalation, which is a combination of earth and air combined, is smell. That is why Heraclitus also said that if everything that exists were to become smoke noses would discern it. (Aristotle - On the soul p.82 443a 23)