"When an Ego, a human soul, by vicious appetite or otherwise, forms a very strong link of attachment to any type of animal, the astral body (Kamarupa) of such a person shows the corresponding animal characteristics, and in the astral world, where thoughts and passions are visible as forms, may take the animal shapes; thus, after death, in _Pretaloka_, the soul would be embodied in an animal vesture, resembling or approximating to the animal whose qualities had been encouraged during earth-life. Either at this stage, or when the soul is returning towards reincarnation, and is again in the astral world, it may, in extreme cases, be linked by magnetic affinity to the astral body of the animal it has approached in character, and will then, through the animal's astral body, be chained as a prisoner to that animal's physical body. Thus chained, it cannot go onwards to _Svarga_, if the tie be set up while it is a _Preta_; nor go onwards to human birth, if it be descending towards physical life. It is truly undergoing penal servitude, chained to an animal; it is conscious in the astral world, has its human faculties, but it cannot control the brute body with which it is connected, nor express itself through that body on the physical plane. The animal organisation does not possess the mechanism needed by the human Ego for self-expression; it can serve as a jailor, not as a vehicle. Further, the "animal soul" is not ejected, but is the proper tenant and controller of its own body. S'ri Shankaracharya hints very clearly at the difference between this penal imprisonment and becoming a stone, a tree, or an animal. Such an imprisonment is not "reincarnation," ... the human Ego "cannot reincarnate as an animal," cannot "become an animal." "In cases where the Ego is not degraded enough for absolute imprisonment, but in which the astral body has become very animal, it may pass on normally to human re-birth, but the animal characteristic will be largely reproduced in the physical body--as witness the "monsters" who in face are sometimes repulsively animal, pig-faced, dog-faced, &c. Men, by yielding to the most bestial vices, entail on themselves penalties more terrible than they, for the most part, realise; for Nature's laws work on unbrokenly and bring to every man the harvest of the seed he sows. The suffering entailed on the conscious human entity, thus cut off from progress and from self-expression, is very great, and is, of course, reformatory in its action; it is somewhat similar to that endured by other Egos, who are linked to bodies human in form, but without normal brains--those we call idiots, lunatics, &c. Idiocy and lunacy are the results of vices different in kind from those that bring about the animal servitude above explained, but the Ego in these cases also is attached to a form through which he cannot express himself."