On the face of it, Heraclitus seems to have little to say about aesthetics or the philosophy of art. He does anticipate Plato in criticizing the poets Homer and Hesiod for telling lies. And he also has some important things to say about harmony. One might leave it there, but I always like to look at the great philosophers from an aesthetic point of view and Heraclitus has a lot to offer in that regard. He certainly influenced Nietzsche, Heidegger and Derrida among the modern greats (Derrida's idea of a deconstructive reading seems to me just an extension of Heraclitean theory of interpretation, the dynamic of opposites playing a central role in both philosophers.) I will be using mainly the Robin Waterfield translation of the fragments as appearing in The First Philosophers: The Presocratics and the Sophists (Oxford, 2000) and my discussion is greatly influenced by his arrangement and commentary. However, that is almost arbitrary since different classical scholars arrange the fragments differently and some have interestingly different translations, or shed light on the meanings of specific terms. In particular, I am inspired by Edward Hussey "Heraclitus" in The Cambridge Companion to Early Greek Philosophy ed. A. A. Long, Cambridge University Press, 1999.
I make no claims to be a Heraclitus scholar: mainly I am interested in engaging in a dialogue with Heraclitus. On a personal note, Heraclitus is one the first philosophers I ever fell in love with, probably at the age of fifteen. I had read The Aristos by John Fowles and went from there to his source. Reading Heraclitus at a young age probably gave me a lifelong skepticism concerning rationalism and any logic-centered philosophy that does not give sufficient credit to the way that tensions can underlie harmonies and the way opposites can be internally related. Heraclitus is not an aesthetic philosopher just because he talks about harmonies but also because these harmonies, or what Hussey calls "latent structures" are metaphor-like. Looking at the world fundamentally through metaphors is, I would argue, an aesthetic way of looking. The metaphysics we get from this mirrors the epistemology and methodology insofar as aphorisms that are riddles (of the sort that make up the fragments of Heraclitus) are kinds of metaphors that reveal something that is itself essentially metaphor-like. Unlike Plato's view of essences, Heraclitus's makes the philosopher's quest not for final definitions but for deeper knowledge of this metaphorical dimension of reality. Moreover, the symbol of fire, so central to Heraclitus, I understand as referring to the quality of aura, the glowing sense of life that emerges when such a quest is successful. This aura emerges from or adheres to the interpretive object in the process of interpretation, what Heidegger refers to as an opening up of Being. We refer to this aura when we say that something is beautiful, but an aura can also be negative, as when something is ugly. Successfully deep riddles are metaphors that reveal tensions of vibrant reality beneath the superficial categorizations of everyday thought. The "logos" that Heraclitus seeks to express is, then, wrongly read as "logic" or even, as Hussey would have it, reason in the sense of the proper proportion in which everything fits (93). This would accord, I think, too nicely into our current conception of the rational as a matter of conclusions based on correct definition, valid demonstration, resistance to counterarguments, and premises grounded in sound experiment-based or data-driven evidence. All of that is a fine and workable notion of rationality, but a counter notion of logos allows another dimension of rationality that may at first seem irrational but ultimately is not, one that gives credit once again to insight into essences as expressed in metaphors and riddles and not in traditional real philosophical definition, i.e. definition in terms of necessary and sufficient conditions (what Socrates ostensibly sought).
Begin with the fragment, "Harmony: non-apparent is better than apparent." Apparent harmony is what we see easily enough in conventional modes of thinking where categories are applied in familiar ways. But when category violation occurs in metaphorical thinking (e.g. "man is a wolf to man" is a category violation since man is not literally a wolf), new and more powerful harmonies emerge, ones that are not easy but that in fact contain possibly disturbing tensions. If we add to that the idea "I searched for myself" and that "the true nature of a thing tends to hide itself" we can get the notion that the true nature of things, including the searcher him or herself, is hidden. Since it is a hidden harmony it is a better one, better because deeper.
In what way are such harmonies hidden? We know that "eyes and ears are bad witnesses for men if they have souls which cannot understand their language." So these harmonies are hidden from eyes and ears unless we can understand the language of eyes and ears, unless we interpret, i.e. unless we question the surface story. So when Heraclitus says "the things I rate highly are those which are accessible to sight, hearing, apprehension" he means that the senses have a power of penetration to hidden harmonies, one of which we are not normally aware. And of course these are the senses by which we typically apprehend aesthetic phenomena.
We also have the central metaphor of the lyre and the bow. The harmonies of these stringed instruments are hidden when we just look at them. Moreover, they are based on tensions that are hidden as well. Heraclitus says that the many are "ignorant of how while tending away it agrees with itself - a back-turning harmony, like a bow or a lyre." From this we see a way to understand the principle that "war is father and king of all." War is the principle of a conflict between principles that produces harmonies. This passage also says that war reveals some "as gods, others as men; some he makes slaves, other free." We know that actual war makes these changes: we also know that war, conflict, and change in general, can make something the opposite of what it was, a slave for example can become free.
Hussey's translation of the lyre passage adds something: "They do not understand how the diverging agrees with itself: a structure [harmonie] turning back on itself, such as that of the bow or of the lyre." Hussey observes that the "unity is more fundamental than the opposites" that "the opposites are essential features of the unity," and that "the manifestation of the opposites involves a process, in which the unity performs its essential function." (96-97)
This constant process of change in which things become their opposites is a process of harmony: here "cool things become warm, warm things cool down" and so forth. So, when Heraclitus says that "war is common, and strife is justice, and ...everything happens in accordance with strife and necessity" we see that conflict is universal and that justice is not a matter of some quiescent harmony but one based on strife. The reference to "necessity" indicates that there are laws that govern change. This is central to the philosophy of Heraclitus: there is constant change but there is also unity, and this is a unity of harmony based on opposing tensions. So, looking at his most famous saying, the reason why "on those who step into the same rivers ever different waters are flowing" is that the river is maintained as the same despite constant change of the substance of which it consists. There is unity in diversity, which is another definition of beauty, for example offered by Hogarth.
Another possible focus for an aesthetic take on Heraclitus can be found in the passage "God: day/night, winter/summer, war/peace, fullness/hunger. He changes like first which, when mixed with spices, is named according to the savor of each." It may seem superficial at first to mention here the idea of "savor" in relation to aesthetics. Hussey observes that when Heraclitus says that day and night are one he means not that they are identical but that they are one thing in different states. Further, this one thing is God, as we see in this quote, which is to say that the unity manifests something divine or divine-like insofar as there is an aura of the infinite here. God here is not seen as an unchanging entity but rather as nature itself but in its divine aspect, and manifested through the sensually pleasurable experience of tastes as associated with the savor of things when mixed with spices.
I want now to focus on one passage, originally quoted by Sextus Empiricus, and quite a long one: "we become intelligent by drawing in this divine reason, and although we become forgetful when asleep, we regain our intelligence as soon as we wake up. For since when we are asleep the sensory channels are closed, mind-in-us is separated from its natural union with what surrounds us (the only lifeline, so to speak, which is preserved being connected by means of respiration), and so, being separated, it loses the power of memory that it formerly possessed. But when we wake up, our mind again peeps out through the sensory channels, as if they were windows, makes contact with what surrounds us, and is endowed with the power of reason. Just as cinders which are brought close to a fire undergo an alteration and start to glow, but are extinguished when they are separated, so the fraction of what surrounds us which is in exile in our bodies becomes more or less irrational in a state of separation, but in a state of union, which is achieved through the numerous sensory channels, it is restored to a condition of similarity to the whole." (Waterfield T9 44-45.)
This can be read in one way as remarkably similar to Plato's Pythagorean stories of the soul as separate and distinct from the body and as containing a portion of the divine fire. But it might be read in another way (by reading it as itself an allegory or metaphor), as more deeply aesthetic, where "divine reason" is what happens when things light up in the aura of their essences revealed, this happening only when humans wake up from their usual sleepy ways of thinking, remembering by way of using their senses, not only to see in a superficial way but to see in the sense of allowing beauty to emerge. Memory here acts not just as a storage vehicle but as something active, some what like Plato's notion of recollection (perhaps Plato got the idea from Heraclitus). The "power of memory" and the "power of reason" as also "intelligence" are one on this account: it all has to do with our "natural union with what surrounds us" i.e. by way of our "sensory channels." The idea of essences being revealed can be seen in the notion of "physis" or nature when Heraclitus says "nature likes to conceal itself."
In this reading, being "endowed with the power of reason" is not a matter of learning logic or being able simply to mount arguments or even to have the skill to reject dubious premises, but the ability (also, but fundamentally so) to be open to insight concerning the emerging and constantly changing essences of things, the ability, without which, all of the other appurtenances of reason are useless or, worse, deceptive.
An important aspect of this is that access to what surrounds us is by way of the senses, hence related to the Greek "aesthesis" and that the thing perceived is not just in us but in the world, hence not merely subjective. These are not essences to be found in an ideal world of Forms of the Platonic sort. They are more like Aristotelian universals, but unlike these, as we have seen, they are accessed primarily through the senses, thus connecting Heraclitus more with Lucretius, Nietzsche and Dewey. Cinders brought close to the fire and that start to glow indicates that when essences are revealed there is a glowing aura, that the object perceived is as if more than itself. Fire, in my reading represents that aura. The cinders image indicates how the subjective/objective split may be overcome. The whole, on this account, is the aura that comes with any sense of unity, but also a reference to the background of the universe as a whole, which also provides aura as something like background radiation from the big bang (to use a metaphor). If all of this is too mystical sounding for you I would suggest that I believe it could all be expressed in the pragmatist language of Dewey.