The soul, of which it is said that it shall live after death, is nothing but the man himself, who lives in the body; that is, it is the interior man, who by the body acts in the world, and enables the body to live. The commerce of the soul with the body is the communication of the spiritual things of heaven with the natural things of the world, and the communication is effected by influx, and is according to conjunction. This communication, which is effected by influx, according to conjunction, is at this day unknown, because all things are attributed to nature, and nothing is known of the spiritual, which at this day is so remote, that, when it is thought of, it appears as nothing.
from Arcana Coelestia, Section 6054, 6057
Secrets of Heaven 