When I read this from Primo Levi…
“It’s easy enough to say that the same causes should produce the same effects, but this notion was invented by people who don’t do anything themselves but have everything done for them. Try asking a farmer, or a schoolmaster, or a doctor, or, especially, a politician about that: if he’s honest or intelligent, he’ll laugh in your face.”
…I was sceptical. Surely, there are some things which do have the same effect? This scepticism lasted only for a moment, though, because the teaching of Heraclitus came to mind: We can never step in the same river twice.
Every moment, from the beginning of time into the furthest reaches of the future, stands alone and unique. The distribution of matter and the content of the Universe is never twice the same. So it makes sense for Levi to assert that the same causes do not produce the same effects—the same cause cannot be applied in the same scenario, therefore the results must differ.
This is perhaps why those who cling to past methods so often find failure in the future. “What worked once will work again” they think. It won’t. The world is different, even though it does not look it.
This makes a mockery of the concept of precedent—what has happened is only a slight indication of what will. Every moment we encounter is, truly, new. Every decision we must take represents a step into a new river.