18. When the spirit must incarnate in a human body in process of formation, a fluidic connection, which is none other than an expansion of the perispirit, attaches it to the germ toward which it finds itself attracted by an irresistible force from the moment of conception. By measure, as the germ unfolds, the connection shortens. Under the influence of the vital material principle of the germ, the perispirit, which possesses certain properties of matter, is united molecule by molecule with the forming body; whence one can say that the Spirit, through the perispirit, takes root in the germ, like a plant in the Earth. When the germ is entirely developed, the union is complete, and then it is born into outward life.
By contrary effect this union of the perispirit and flesh, which was accomplished under influence of the vital principle of the germ, when the principle ceases to act in consequence of the decay of the body, death is the result. The union which was only maintained by an active force ceases when the force ceases to act; then the perispirit detaches itself molecule by molecule, as it was united, and the Spirit is rendered free. It is then not the departure of the Spirit which causes the death of the body, but the death of the body which causes the departure of the Spirit.
Therefore, instants after death the integration of the spirit is complete; in fact, its faculties acquire a greater perspicuity, whereas the principle of life is extinguished in the body. This is by itself an evident proof that the vital principle and the spiritual principle are two different things.