What are the limits of incarnation? When we speak of the sheath that forms the body of the spirit, incarnation has no exactly defined boundaries, for the materiality of this sheath diminishes as the spirit purifies itself.

On some worlds more advanced than Earth, this body is less compact, less heavy and less dense, and therefore less subject to vicissitudes. At a higher level, it is permeable and almost fluid. From level to level it dematerialises and eventually merges with the perispirit.

According to the world in which it has to live, the spirit adopts the sheath which corresponds to the nature of this world. The perispirit also undergoes a gradual transformation. It becomes more and more ethereal until it reaches the complete purity that characterises pure spirits.

Although there are special worlds intended for the residence of highly developed spirits, they are not subject to them, as is the case in the lower worlds. The state of detachment in which they find themselves enables them to go where the tasks entrusted to them call them.

If we consider incarnation from the material point of view, as it takes place on earth, we can say that it is confined to the lower worlds. It is therefore up to the spirit to free itself from it more or less quickly through the work of purification.

It must also be borne in mind that in the wandering state, that is to say, in the interval of corporeal existences, the situation of the spirit is related to the nature of the world to which its degree of progress binds it. Thus, in impermanence, the spirit is more or less happy, free and enlightened, according as it is more or less dematerialised.