Nephesh

Nefesh is the first and lowest of the levels of soul in the Kabbalistic scheme, and it is the term with the deepest biblical roots: in the Hebrew Bible nefesh means the living being as such, the throat, the breath, the appetite, and it is used of animals as well as of people, so that Genesis 2:7 has the human become a nefesh hayyah, a living creature. Kabbalah takes it as the vital soul, bound to the body and to the blood, present from birth, the seat of appetite and of the instinctual life; the Zohar treats it as the level that all possess without effort, the others being acquired or awakened. It is the level associated with Assiah, the world of action, and the sefirah Malkuth in the standard correspondences.

Later Hasidic teaching sharpened the idea further. In the Tanya of Shneur Zalman of Liadi, the founding text of Chabad Hasidism written in the late eighteenth century, every Jew is held to possess two nefashot, an animal soul, nefesh habahamit, rooted in the physical vitality of the body and capable of both permitted and selfish desire, and a divine soul, nefesh haelokit, a spark of holiness clothed within it; the moral life is described there as the ongoing contest between the two for control of a person's thought, speech and action, the three "garments" through which any soul-level is held to express itself in the world. That framing gives the oldest and most basic of the five levels a psychological complexity the earlier Zoharic material states only briefly.

Sources The ZoharTraditionally attributed to Moses de Leon with Tanya (Likkutei Amarim)Shneur Zalman of Liady

Jewish mourning custom draws directly on the layered soul the Kabbalistic sources describe, and Nefesh, the lowest and most closely bound to the body, is held to linger near the grave for a period traditionally counted as the first year after death, while the higher levels are said to depart more quickly toward their source. This belief is offered by some authorities as part of the reasoning behind the graduated structure of Jewish mourning, an intense first week, a lighter first month, and a fuller mourning period extending to a year for a parent, though the practices themselves rest on a wider set of biblical and rabbinic sources than the soul doctrine alone.

Because Nefesh is the level most tied to bodily appetite and instinct, some later ethical and Hasidic writers describe the ongoing recitation of psalms and charitable acts in a mourner's name as work that helps elevate a relative's Nefesh, refining what was most animal and appetite bound in the person now that it can no longer act through a living body.

This practical, mourning centred use of the soul scheme sits alongside its more abstract role in Kabbalistic cosmology, where Nefesh corresponds to the lowest of the Four Worlds; the funerary use treats the same doctrine as something to act on rather than only something to describe.