The ancient Greek philosopher Heraclitus famously said that one cannot step into the same river twice. But what does this really mean? And what can we learn from this for our own lives?
This article is part of The Ultimate Guide to Epicurus.
It is the same Sun?
You may have heard the old adage that one cannot step into the same river twice. It’s normally attributed to the ancient Greek philosopher Heraclitus (~535–475 BC), who also said something much fresher and more surprising: that we should think of the Sun as a new Sun every day, rather than the same old ball going down in the evenings and rising again the next day.
And, in a sense, he’s right. Of course, what we call the Sun is the same star every day. It isn’t made anew when we sleep. It keeps burning on, shining on other places, far away, and comes back in the morning to wake us up for work. That’s one way of seeing things.
But seen another way, it is a new Sun every day. In a trivial sense, it has burned off yesterday’s hydrogen into helium, and what I see burning now is fresh hydrogen, fresh material being converted into energy, into warmth and light. The Sun of today is different from yesterday’s. It is one day closer to its final burn-out. It’s a few million kilometres further along its path around the centre of the Milky Way, and all of us with it. Like the river into which I cannot step twice, the Sun will also never be exactly the same.
If we look a little deeper into what Heraclitus is saying here, it is a surprisingly interesting meditation on what makes things what they are.
If the river is always flowing along and yesterday’s water is now already gone and part of the ocean, what is it actually that is still there for me to identify as the same river? We know that the human body replaces most of its cells, one by one, over the course of seven to ten years. If you’ve been married for seven years, the person you thought you took as a husband or wife has long disappeared down various drains – and another is now standing in their (new) skin. So what makes this new copy of something that looks like my spouse, my friend, my child – what makes them the person I love?
In Buddhism, it’s the Five Aggregates: the form of our bodies, the sensations of our senses, awareness, volition and consciousness. In a more simplified way, one could say that we are our consciousness, the subjective point at which our experiences of the world are felt and converge, the point from which our emotions, responses and intentions originate.
Epicurus (341-270 BC)
Epicurus (341-270 BC) is often seen as an advocate of a luxurious life, rich in good food and other pleasures. This is incorrect.
But this does not help very much. How do I know that you are still the same? Every person only has access to their own consciousness. If one’s consciousness is all that identifies a person, how do I know that the consciousness of my children has not changed over the past seven years? Wait — it very likely has. So then, where are my children, the ones I knew when they were small?
Perhaps they’re nowhere. Like a fire (what is a fire, anyway? Fire is a flow of matter, of carbon particles and heated gas), like a river, a human being is a not a thing but a flow. And so is everything else. What is the most stable thing we can think of? A rock perhaps. A boulder, unchanged for millions of years. But permanence is really an illusion of our senses, an artefact caused by our short lifespans. A rock looks as permanent to us as we must look to an insect that lives only a day — and yet, in our own time scale, our lives are short and fleeting. So, in its own time scale, the rock also grows, tectonic plates shift, mountains rise out of the seas and lava from the Earth’s interior continuously forms new land.
And perhaps the proper part of speech to talk about human beings, as well as everything else really, are not nouns (“that dude,” “my kids”) but verbs. “That mountain” gives an air of permanence to the thing, just as “that flame” does. But both mountain and flame are temporary, things in flow, growing, moving, eternally changing. A mountain, a flame and my children could be better, more truthfully be addressed with verbs: “that mountaining,” “that flaming,” “that … kidding?” – (Just kidding).
How static are pleasures?
Epicurus has a similar idea. Being an atomist, he believed that everything in the world is made up of little bits of matter, the atoms, that constantly arrange and re-arrange themselves to form everything we see. For him, the idea of non-permanent things, of things in flux, came very naturally.
Pleasures too, Epicurus knew, come and go in time. Some are short-lived, like the pleasure of eating a piece of chocolate. There’s nothing much wrong with them, except that they don’t last very long. We have to put in a lot of effort in order to be able to afford that chocolate, and then, in a short moment of time, it’s eaten and gone. Five minutes after eating it, its taste has disappeared and only the calories and our ever widening bodily periphery remain to remind us that we ever tasted it.
But look, says Epicurus. Some pleasures are less fleeting. The chocolate might be gone in an instant, but the feeling of not being hungry any more remains for a longer time. And now, if we look closer again, we’ll see that the feeling of being not-hungry, that pleasurable absence of wanting food, is actually the same, no matter what we’ve eaten. A piece of bread will take hunger away just as well (or better) than a piece of the most expensive chocolate. The difference between the two is just what matters the least, because it’s the most fleeing property of food: its taste. What stays with us much longer, the calories, the vitamins, the minerals, the absence of hunger — these are the things that we ought to seek in good food, and these are what really matter to our long-term happiness.
So it is not only our bodies that are in constant flow, but our sensory impressions too. Pleasures come, excite our senses and vanish again in the blink of an eye. Isn’t it strange, Epicurus says, that we should devote so much of our lives to chasing something so fleeting, something that has so little lasting value?
This is why the wise man, he adds, should strive only for these pleasures that last longer, the more constant ones: not being hungry. Having good friends. Being at peace. And these are surprisingly easy to get if we stop chasing the same ephemeral things that everyone else wants.
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The Ultimate Guide to Epicurus
A comprehensive overview of Epicurus’ philosophy of happiness. Epicurus is one of the few ancient philosophers who are more relevant today than they were in their own times. Learn all about him right here.
Finding happiness among change
Epicurus himself probably didn’t quite see it this way, but the difference between the “moving” pleasures (eating a piece of chocolate) and what he calls “static” pleasures (being non-hungry) is not really a difference in kind. It is a matter of time scales. Everything comes and goes, or, as Heraclitus is credited with saying, “panta rhei”: everything flows. Rivers, flames, our pleasures, and ourselves. When the time scale in which things flow approaches or exceeds the time scale on which we live out our lives, then we think of these things as relatively “static”. But they, too, will eventually go. Being full is not a lasting feeling. Eventually, the hunger will return. Eventually, the peace of mind of the best Epicurean will go out the window and we will fret over one stupid thing or another.
And so Heraclitus maybe is right, after all. Not even the Sun is the same every day. But that’s no grounds for resignation, not for Heraclitus and not for Epicurus. It is, Heraclitus says, a new Sun every day. A new chance to live our lives in a better, richer, more thoughtful and more satisfying way.
Because we, like the Sun, are reborn new every day.
Return to The Ultimate Guide to Epicurus.
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