Impermanence

Impermanence (Pali anicca, Sanskrit anitya, "not-lasting") is the simple but far-reaching observation that everything assembled from parts and conditions is in constant flux. Mountains erode, bodies age, moods shift, thoughts arise and vanish in an instant. Nothing that comes together stays exactly as it is; whatever has a beginning also has an ending, and a continual changing in between. This is meant not as gloomy poetry but as a plain description of how things actually are.

Impermanence is one of the "three marks of existence," the three features Buddhism says hold true of all conditioned things (the other two being unsatisfactoriness and non-self). The three are deeply linked: precisely because pleasant things don't last, clinging to them as if they could brings disappointment; and because everything is shifting, there is no permanent fixed self to be found among the changes either.

Far from being depressing, this teaching is meant to be freeing. If you truly absorb that experiences are passing, you can hold them more lightly: enjoy good moments without desperately grasping, and meet hard ones knowing they too will pass. Meditators are encouraged to watch impermanence directly in their own minute-to-minute experience, observing sensations and thoughts come and go. Seeing change clearly, the tradition says, gradually loosens the craving that keeps suffering going, and points toward nirvana, the one unconditioned peace that is not itself swept along in the flux.