Heraclitus famously said, “You cannot step into the same river twice.” He continued that thought with an explanation: “For it is not the same river and you are not the same person.”
This is an even more radical statement than the more common phrase, “You can’t go home again.” We can follow the logic Heraclitus sets up: “For it is not the same home and you are not the same person.”
Heraclitus’ idea is more radical because he is suggesting a step and then an immediately following step. Not much time has passed. It’s not like growing up in a house and then going back there as an adult and realizing that everything is smaller than you remember.
No. Heraclitus is talking about constant change from one moment to the next. Change that we ourselves have perhaps not even noticed: a step and another step immediately following: That, Heraclitus is saying, is the nature of reality: Constant change.
In sculpture and painting Heraclitus is usually portrayed as The Weeping Philosopher. He can be mistakenly seen as praying because of his usual visual portrayal with a bowed head. He’s not praying. He’s weeping. Tradition says that he had an extremely melancholic personality. (BTW, Democritus, the philosopher who postulated the existence of atoms, is known as The Laughing Philosopher.)
Heraclitus believed that this material reality that we see is the only one. And he believed — apparently mistakenly — that the material cosmos is eternal, the implication being that no gods made this world. It has always been here.
Whether or not he was correct on that point of an eternal cosmos, Heraclitus’ thinking had implications very unlike the mythologies in which particular gods create the earth.
In an uncreated cosmos, no gods are required to make it, and the cosmos does not require any gods to keep an eye on its operation: the cosmos is merely here.
In which case, yes, water will flow and everything changes: we are ephemeral creatures. But in this vision of reality, there is no will of any god to be appeased or appealed to.
Heraclitus pointed toward a different reality from that imagined by the majority of his Mediterranean contemporaries: We are on our own.
That’s a very Humanist vision.
In this way of seeing reality, we human beings have a lot of work to do: We must strive to know about the world in its particular details because the details are all that exist.
We must search for truth in the natural world itself — truth isn’t written in any books inspired by the gods.
And, change alone is unchanging.
Therefore, we find apparent contradictions: Roads go both ways; circles begin where they end. In the thinking of Heraclitus, there is no material world versus spiritual world: all is one.
By studying the details, we can see and even sometimes predict change by watching this thing we learn to call time. In order to discuss and potentially understand this concept of change, we have to develop a concept of duration that contains change, which is why “No one can step into the same river twice.”
Yes, the water continues to flow, and the very temporary biological entity we call a person keeps changing too.
Now, let’s put aside for a moment questions of gray and in-between and consider two stark options.
One option: Heraclitus is wrong: there is another world — an eternal and non-chaotic one, though we can’t see it.
Heraclitus is right: All we have is this material world of often chaotic change. A world we can navigate more safely by watching the details.
With option one: trust that there is an unseen reality and order to the cosmos and do what you can to appeal to and appease that unseen reality;
with option two: trust what we observe of our reality and adapt to those observations.
Traditional Christianity says: there is an unseen reality.
Humanism says: You see it: this is what there is; love the details.
As for me, that’s a big reason why I’m a Humanist.