"War is the father of all and king of all; it shows some to be gods, others to be men, some it makes slaves, and others free."

The above excerpt is perhaps one of the most famous of Heraclitus and is often interpreted as if he were some warlike "dog of war." Although easily memorable due to the poetic nature of his writing, Heraclitus is considered by many to be aphoristic and obscure, which has given him the reputation of being "dark" since antiquity and contributed to his allure. However, the truth is simpler and perhaps even more captivating.
Heraclitus wrote in a dual manner, consciously charging his words with different layers of meaning, which had to (and must) be approached as riddles that are primarily solved experientially and empirically. In other words, his truth lies beneath the surface of the words he uses.
The main pillars of his thought were that a) people must know the Logos (a unifying, objective principle), b) the world is constantly changing, c) the essence of the world is eternal fire (fire symbolizes continuous change), and finally d) the balance, solidity, and harmony of the world is maintained through continuous movement, competition, and the interweaving of opposites.

Given that his work survives in fragments, one initial innovation of his seems to be the introduction of the human element into cosmology, inaugurating in pre-Socratic cosmogony the anthropocentrism that would come to monopolize classical thought. Thus, although he is presented by sources as an antisocial character—and for some, a misanthrope—Heraclitus may have been the first humanist philosopher.
A second innovation of his was that, although at first glance he appears as a monist (everything comes from one element and consists of variations of it, which in his case is fire), Heraclitus radically alters his generative element: "from fire, the first change is sea; and from sea, half is land, and the other half is fiery current"—that is, the changes of fire are initially into sea (not generally water), and from sea, half is land, the other half is fiery stream (hurricane, whirlwind). Therefore, Heraclitus' fire can qualitatively transform into anything, and everything can be turned into fire ("the exchange of fire is all things and fire is all things").

Returning to the excerpt about war, therefore, Heraclitus obviously does not mean armed conflict but the palindromic or retrograde harmony (thesis-antithesis-synthesis), that is, the competitive, opposing forces that act simultaneously to produce balanced and harmonious work, as happens on the vibrating string of a musical instrument to produce sound.

In an era when demonstrative reasoning was still in its infancy, Heraclitus uses commonly accepted empirical examples. And his influence extends from his contemporaries to our days; especially in our days.

In conclusion, Heraclitus is not read, studied, or philosophized; he is lived.