The Spirits' Book
Book Two - The Spirit World
Chapter VII - Return to Physical Life
Union of Body and Soul – Abortion
345. Is the union between the spirit and the body conclusive from the moment of conception? Could the spirit, during the initial period of that union, abandon the body that has been assigned to it?
“The union is conclusive in the sense that no other spirit could replace the one to whom the body has been assigned. But, as the link that binds the body and soul is very weak at first, it can be easily broken and severed by a spirit who abandons the trial it had chosen. When this happens, the child does not live.”