Nor is it certain that, when the man is free from this, he will at once become conscious of the astral world. For there is in him a good deal of the lowest kind of astral matter, so that a shell of this may be made around him. But he may be quite unable to use that matter. If he has lived a reasonably decent life he is little in the habit of employing it or responding to its vibrations, and he cannot instantly acquire this habit. For that reason, he may remain unconscious until that matter gradually wears away, and some matter which he _is_ in the habit of using comes on the surface. Such an occlusion, however, is scarcely ever complete, for even in the most carefully made shell some particles of the finer matter occasionally find their way to the surface, and give him fleeting glimpses of his surroundings. There are some men who cling so desperately to their physical vehicles that they will not relax their hold upon the etheric double, but strive with all their might to retain it. They may be successful in doing so for a considerable time, but only at the cost of great discomfort to themselves. They are shut out from both worlds, and find themselves surrounded by a dense grey mist, through which they see very dimly the things of the physical world, but with all the colour gone from them. It is a terrible struggle for them to maintain their position in this miserable condition, and yet they will not relax their hold upon the etheric double, feeling that that is at least some sort of link with the only world that they know. Thus they drift about in a condition of loneliness and misery until from sheer fatigue their hold fails them, and they slip into the comparative happiness of astral life. Sometimes in their desperation they grasp blindly at other bodies, and try to enter into them, and occasionally they are successful in such an attempt. They may seize upon a baby body, ousting the feeble personality for whom it was intended, or sometimes they grasp even the body of an animal. All this trouble arises entirely from ignorance, and it can never happen to anyone who understands the laws of life and death.