For the ancient world, Heraclitus was always skoteinos, "dark" and "obscure." This was due as much to his riddling, prophetic style as to the exact nature of the mysterious logos he saw hidden beneath the flow and flux of appearances. Tradition has it that, despite the political privileges that came from his birth into one of the aristocratic families of Ephesus, he rejected rulership in favor of the life of a misanthropic hermit, living alone in the mountains, eating plants and grass. Haughty and aloof, rude and enigmatic, he was famous for his caustic wit and his rejection of most other thinkers as learned but far from intelligent or wise. The tradition itself seems to have had the last laugh—(planned revenge?)—on the arrogant philosopher, however, since it records that he died at the age of sixty after burying himself up to the neck in hot cow dung in an attempt to cure himself of dropsy.

Some quotations (tr. McKirahan, edited) from the one book attributed to him, and entitled On Nature:

(1) The logos [word/account/measure/proportion/arrangement/order/rational principle] is just as I describe it, but men are always incapable of understanding it, both before they hear it and after they have heard it for the first time. For though all things happen according to this logos men are like people of no experience, even when they experience such words and activities as I explain, when I distinguish each thing according to its constitution and declare how it is. But the rest of men fail to notice what they do after they wake up just as they forget when they do when asleep. [197]

(2) Therefore it is necessary to follow what is common to all; but while the logos is common, most people live as if they had a private understanding. [198]

(3) Listening not to me but to the logos it is wise to agree that all things are one. [199]

(4) To those who are awake there is one ordered universe common to all, whereas in sleep each man turns away into a world of his own. [89]

(5) This kosmos [world-order] was made by no god or man, but it always was and is and will be everliving fire, kindling in measures and going out in measures. [220]

(6) Fire lives the death of earth, air lives the death of fire, water lives the death of air, earth that of water. [76]

(7) Cold things grow hot, hot things grow cold, the wet dries, the dry is moistened. [126]

(8) The road up and the road down is one and the same. [203]

(9) Sea is the purest and the most polluted: for fishes, drinkable and healthful; for men, unpotable and harmful. [202]

(10) Disease makes health pleasant and good; hunger, satiety; weariness, rest. [204]

(11) Immortal mortals, mortal immortals, living their death, dying their life. [242]

(12) It is not possible to step into the same river twice. [91]

(13) It is necessary to know that war is common and right is strife and that everything happens through strife and necessity. [214]

(14) A mixed drink [kykeon: a mixture of wine, grated cheese and barley] also separates if it is not stirred. [125]

(15) War is father and king of all, and some he shows as gods, others as men; some he makes slaves, others free. [215]

(16) They do not see how by being at variance it agrees with itself: there is a back-stretched harmony, as in bow and lyre. [212]

(17) Nature loves to hide itself. [211]

(18) The unseen harmony is stronger than the visible one. [210]

(19) Thunderbolt steers all things. [223]

(20) One thing, the only truly wise, is both willing and unwilling to be called by the name of Zeus. [231]

(21) God is day/night, winter/summer, war/peace, satiety/hunger. But he changes like fire which when mingled with the smoke of incense is named according to each man's pleasure. [207]

(22) To God all things are beautiful and just, but men have supposed some things just, others unjust. [209]

(23) I searched myself out. [249]

(24) Soul has its own logos,which increases itself. [115]

(25) You could not discover the boundaries of soul, even by travelling along every path: so deep is its logos. [235]

(26) Man's character is his daimon [god/power/destiny]. [250]

(27) The lord whose oracle is at Delphi [i.e. Apollo, god of prophecy] neither speaks out nor conceals, but gives a sign. [247]

(28) The name of the bow [biós] is life [bíos], but its work is death. [48]