Heraclitus proposed that everything was in flux always:

The Greeks before Heraclitus focused on the essence of things, its nature and being, which they deemed unchangeable. In contrast, Heraclitus said: "You cannot step into the same river twice, for fresh waters are ever flowing in upon you." This simple sentence expresses the gist of his philosophy, meaning that the river isn't actually the same at two different points in time.—It is a radical position and Heraclitus was the [first] to conceive it. He looked at everything being in the state of permanent flux and, hence, reality being merely a succession of transitory states. He told people that nothing is the same now as it was before, and thus nothing what is now will be the same tomorrow. With this he planted the idea of impermanence into Greek thought, and indeed, after Heraclitus Greek philosophy was not the same anymore.

Under such a system, it seems to me that knowledge will be impossible since as soon as you discover the truth of a proposition, the state of the universe changes and either the proposition itself changes or the facts that you used to justify the proposition are open to change. Therefore, at most, you can say that something was true at such and such a time, but it might not be true anymore.

The question isn't whether or not Heraclitus was correct in his understanding of the nature of events. Rather, does his theory of constant flux imply that knowledge does not exist?

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    Knowledge is based on concepts which are abstractions. The abstraction hides the changing nature of things. The abstractions do change but the timeframe is a lot longer (e.g. human generations). Therefore this abstraction, or model, provides a stable platform for knowledge.
    – leancz
    Oct 26, 2012 at 8:54
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    This entry may clear things up: plato.stanford.edu/entries/heraclitus/#Kno
    – danielm
    Oct 26, 2012 at 19:12

2 Answers 2


I don't see that Heraclitean metaphysics denies the possibility of knowledge; as you point out, it requires that knowledge be time-dependent, but this is not an insurmountable obstacle.

I think that it may be instructive, in this regard, to look at the various schools of Buddhist epistemology, which are similarly built upon a premise of the impermanence (indeed, momentariness) of all phenomena. Mark Siderits has a chapter on this in his Buddhism as Philosophy: An Introduction, and for a fuller account, one could turn to Dan Arnold's Buddhists, Brahmins, and Belief or any of the voluminous secondary literature on Dharmakīrti.

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    This reply is mostly off-topic: the question is explicitly about the Heraclitean system. The parallel with Buddhist thought is, while interesting, beside the point. Also, it would be interesting to know if there is textual evidence that Heraclitus accepted the existence of eternal facts such as at t, p, or whether that is a somewhat anachronistic, contemporary reading.
    – Schiphol
    Oct 26, 2012 at 18:18
  • I might suggest exploring the two through the notion of wisdom -- I.e., how might we understand/reconcile Heraclitus' use of the word "wisdom" with the momentariness of knowing?
    – Joseph Weissman
    Oct 26, 2012 at 20:28
  • I would argue, based on a reading of the historical sources, that the Heraclitean metaphysics is largely identical to the Buddhist one in this respect. As for the existence of external facts, Heraclitus said "Though the logos is common, the many live as if they had a wisdom of their own." Oct 27, 2012 at 13:16
  • My worry was about eternal, not external facts :) Those that happen for all eternity, because indexed to a certain time.
    – Schiphol
    Oct 28, 2012 at 4:46

Knowledge is possible, in the sense that are abstract hidden old schools of thoughts or forms that come and form in human essence. These ideas came into arithmetic form, which make someone justify his logical reason. According to ancient ardent John Locke, said in his theory knowledge come from experience. That reasoning is the mother of knowledge, because is the foundation of knowledge.

  • Hi Garba. I fixed a few spelling and capitalization errors; feel free to edit again if I messed anything up. But I don't think this particularly answers my question. How does this answer relate to the ideas of Heraclitus? May 16, 2013 at 20:29
  • I think the spelling errors were more or irrelevant compared to the grammar errors. I have no idea what's going on here.
    – naught101
    May 12, 2014 at 2:24

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