It should be understood that war is the common condition, that strife is justice, and that all things come to pass through the compulsion of strife.
 Heraclitus, On Nature (c. 535 – c. 475 BCE). copy citation

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Author Heraclitus
Source On Nature
Topic justice war
Date c. 535 – c. 475 BCE
Language English
Reference
Note Translated by William Harris
Weblink http://community.middlebury.edu/~harris/Philosophy/heraclitus.pdf

Context

“Time is a child moving counters in a game; the royal power is a child's. (52)
25. War is both father and king of all; some he has shown forth as gods and others as men, some he has made slaves and others free. (53)
26. It should be understood that war is the common condition, that strife is justice, and that all things come to pass through the compulsion of strife. (80)
27. Homer was wrong in saying, "Would that strife might perish from amongst gods and men. For if that were to occur, then all things would cease to exist.
ON NATURE
28. There is exchange of all things for fire and of fire for all things, as there is of wares for gold and of gold for wares.” source