Buddhists accept the doctrine of impermanence, which says roughly that all things are impermanent. And they think that accepting this doctrine is an important step on the path to enlightenment. But what does it mean? Is it true? What are the likely psychological consequences of accepting it? And how should you act if it is true?

What does the doctrine mean?

Maybe simply: nothing lasts forever.

But that’s consistent things lasting for a very, very long time. If you tell me that I will live for “only” a million years, I’m not going to be disappointed.

Maybe Buddhists instead mean to assert the momentariness of all things: nothing lasts for more than a moment. But this is obviously false. For example, the chair that I’m sitting in has lasted for more than a moment. They probably don’t want to deny this.

Or maybe they mean to assert the dynamism of all things: nothing stays exactly the same from one moment to the next. This fits with what one commentator says:

We cannot say of anything, animate or inanimate, organic or inorganic, “this is lasting”; for even while we are saying this, it would be undergoing change.

But this is consistent with things changing only very slightly from one moment to the next. Maybe my chair is “dynamic” in that its internal temperature constantly fluctuates between 22.6671 degrees and 22.6672 degrees, with no other changes. But this change is insignificant. So long as its appearance and functionality remain the same, I don’t care.

A stronger version of the dynamism claim says that nothing is even a little similar from one moment to the next—that everything is always changing in every respect. But this is obviously false. For example, the number of kidneys I have has not changed in the last ten seconds.

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Maybe this is missing the point. Set aside grand metaphysical claims and just think about humans. There are many good things which, at some level at least, we tend to expect to last longer than they actually do. Things like: our health, the pleasure from eating good meal, cell phone batteries, our looks, our intelligence, razor blades, our talents, friendships, our youth, socks, our lives, and so on.

It’s not that you’ll say you expect to live forever if someone asks you. It’s just that, when you finally learn that you’re going to die soon, you’re not going to shrug and say, “Yes, I knew all along that that was coming”. (Or if you do have this reaction, Buddhists will say you’re already pretty far on the path to enlightenment.) Instead, you’re likely to be distressed and feel like you’ve been given some terrible news.

So maybe Buddhists mean to assert the shortness of good things relative to our expectations: we tend to expect good things to last longer than they actually do.

Is it true?

If it just means that we tend to expect good things to last longer than they actually do, it’s at least plausible, if a little imprecise. On the other interpretations, it’s either obviously false (nothing lasts for more than a moment, everything is always changing in every respect) or plausible but vacuous (nothing lasts forever, everything is always changing in some respect).

What are the psychological consequences of accepting it?

Buddhists seem to think that if you believe something is impermanent, you’ll be less attached to it than you would otherwise be:

The perceiving of impermanence, bhikkhus, developed and frequently practiced, removes all sensual passion, removes all passion for material existence, removes all passion for becoming, removes all ignorance, removes and abolishes all conceit of “I am."¹

But I’m not so sure.

Imagine a couple that can meet for only one night before being separated forever. Is knowing that their time together is impermanent likely to reduce their sensual passion? Or think about how marketers like to say that a sale is for a limited time only. They think that learning of this impermanence will make you more passionate about buying the items on sale, not less.

Or think about someone who is diagnosed with a terminal illness and makes a bucket list. The list likely includes things that they could have done earlier, but simply didn’t care enough to do before they learned of their illness. Learning that their life will end soon makes them care more, not less, about doing these things.

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Maybe this is missing the point. The above quote suggests that the perception of impermanence needs to be “developed and frequently practiced” in order for you to get the results it describes. So maybe the doctrine of impermanence is just supposed to be a tool you can use if you want to eliminate your attachments, but if you don’t use it in the right way, you won’t get that result.

You might still wonder how something that naturally tends to enflame people’s passions, as in the above examples, would be a useful tool for eliminating them. But people are complicated, and I don’t think it’s crazy to think that different people might have extreme opposite reactions to the perception of impermanence, or that you could deliberately nudge yourself into having one reaction or the other.

Of course, all this is just armchair speculation and you’d need to actually look at the evidence to see how accepting the doctrine affects people.

How should you act if it is true?

Buddhists seem to recommend that you should avoid attachment to everything if the doctrine is true. The idea, I guess, is that this minimizes disappointment: if something is impermanent, then there’s a chance you’ll outlive it, and if you’re attached to it, then you’ll be disappointed if you’re still around when it’s gone.²

In some cases, this is the right strategy. For example, many cultures had a tradition of not naming newborn infants until a few months into their lives, presumably to avoid getting attached to them while there was a good chance they were just going to die (infant morality being extremely high throughout most of human history). The cost is that you give up some joy during the first few months of the infant’s life, but the benefit is that you suffer less if it dies. When infant morality is high enough, this is a good tradeoff to make.

But of course no one recommends that you do this now, when infant morality is extremely low.

Instead of indiscriminately giving up attachments, the obvious strategy is to first figure out how long something is likely to last and then work out the expected value of allowing yourself to be attached to that thing, taking into account both your disappointment if you outlive it and the joy and other good things you get from being attached to it while it exists. If you do this, you’ll end up avoiding attachment to some but not all things.

Why isn’t this what Buddhists recommend? Maybe they think it’s too hard give up attachment to only some things, so you’re better off being a purist about it and avoiding attachment to everything, like a recovering alcoholic who refuses all drinks. But this is an extremely high cost to pay just to avoid disappointment, which isn’t the worst thing in the world.