After much meditation the Buddha concluded that everything in the physical world (plus everything in the phenomenology of psychology) is marked by three characteristics, known as the Three Seals or Three Marks.

  • Dukkha or unsatisfactoriness. Nothing found in the physical world or the psychological realm can bring lasting deep satisfaction.
  • Anicca or impermanence. This refers not only to the fact that all conditioned things eventually cease to exist, but also that all conditioned things are in a constant state of flux. (A convenient way to visualize this would be to recall that the atoms constituting your body are constantly being replaced.)
  • Anatta or impersonality. The idea that the human personality or "soul" is an assembly of physical and psychological components, each individually subject to constant flux, and that no central core exists; essentially a bundle theory of mind or soul.

Students of Buddhism often find the doctrine of anatta troubling, because it seems to contradict the Buddhist notion of rebirth: if the human personality dissolves at the moment of death, it is unclear what is reborn. The Buddha avoided metaphysical discussions generally, but clarified this matter somewhat in a conversation with a Brahmin named Kutadanta.