The Buddha identifies three characteristics (tilakkhana) that apply to all conditioned phenomena — all things that arise dependent on causes and conditions. The first is anicca: impermanence. The second is dukkha: unsatisfactoriness or suffering. The third is anatta: not-self. These are not arbitrary doctrinal claims but observations that can be verified through direct experience. Together they describe why clinging to conditioned phenomena — to people, possessions, experiences, even to one's own body and mental states — is a recipe for suffering.
Anicca is not merely the observation that things change over time — everyone knows that flowers wilt and people age. It points to something more radical: that every phenomenon, at every moment, is already a process of arising and passing away. What appears to be a stable object is, on close examination, a rapidly flowing stream of momentary events. The table that seems permanent from moment to moment is, at the level of constituent processes, never the same for two consecutive instants. This is not a scientific claim about atomic physics but a phenomenological one about the nature of experience when carefully observed.
The connection between impermanence and suffering is direct: we suffer because we cling to what cannot be held. We love people who will die, attach ourselves to experiences that will end, seek security in things that will change. The suffering is not caused by the impermanence itself but by the resistance to impermanence — the clinging, the demand that things be otherwise than they are. The insight into anicca, fully absorbed rather than merely understood intellectually, dissolves the compulsive grip of clinging.
Paradoxically, the same impermanence that is the source of suffering is also the ground of liberation. Because nothing is fixed, because no mental state is permanent, because the patterns of reactivity that generate suffering are themselves conditioned and therefore changeable — liberation is possible. If the self were permanent and its habits fixed by nature, change would be impossible. It is precisely because everything, including one's own mental states and character, is impermanent that the path of transformation makes sense.
The Pali word anicca is often translated as "impermanence" or "transience." In Theravada Abhidhamma philosophy, the doctrine of momentariness extends this to the claim that all mental and physical phenomena persist for only a single moment (kshana) before passing away. This ultra-momentariness is philosophically controversial and debated even within Buddhist traditions; the more common presentation treats anicca as the general truth that all conditioned things are in flux.