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.
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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 …
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