The six realms · saṃsāra

The wheel of becoming turns through six destinations — gods, jealous demigods, humans, animals, hungry ghosts, and the hells — and every one of them is temporary, including the heavens, whose inhabitants have the worst problem of all: they are too comfortable to practise. The human birth is the lucky one precisely because it hurts enough to motivate and not so much that it overwhelms. Alone among the Abrahamic mystical systems, the Kabbalah also teaches transmigration — gilgul, the soul returning to complete an unfinished tikkun, sometimes into an animal, sometimes attached to another living person as an ibbur. The premise is shared and the mechanism is not: gilgul moves a specific soul with a specific assignment and ends when the work is done; the round of rebirth moves a causal continuity with nobody in it, and ends when the wanting stops.