consciousness has wonderful possibilities,
and what we commonly call by that name is only the fragment
of it which we can use for the moment. We may perhaps take
an analogy from the action of our physical senses.
There is an enormous gamut of possible vibrations.
One little group of those at a certain level appeals to us as light;
another little group at a much lower level appeals to us as sound.
We are conscious in various ways of other intermediate groups.
But we are fully aware from our knowledge of science that the
gamut extends at both ends far beyond our possibilities of dealing with it.
We may suppose the human consciousness to be like that gamut, and the part of it now in action in the physical brain to correspond, let us say, to the block of oscillations which we call sound. Following out the same analogy, we might suppose our block of astral consciousness to be equivalent to the wave-lengths which we call light; but here again there are many undulations capable of carrying light which we cannot see-- undulations both below and above our limit of vision. In just the same way, below our physical consciousness and above it, and below our astral consciousness and above that, are further sets of vibrations to which our consciousness might be adapted, but is not.
Gifts from Spirit-Word of Knowledge by Allison L. Williams Hill
There are two ways in which it can be adapted;
permanently and intentionally, by the development
of that consciousness so that it can receive more
of those waves which are above and below its normal
possibilities; or temporarily, by some disease or
abnormality which shifts our octave of consciousness
either upwards or downwards. An example of the first
way is the development of psychic powers of all sorts.
But it is unnecessary for me to take up the consideration
of those here, as I have already done it in other books--
Clairvoyance, The Other Side of Death and Some Glimpses of Occultism.
Various drugs have the power of temporarily changing or widening
the scope of consciousness, and therefore they enable us to see things
normally unseen by us, sometimes at the sacrifice of our
ordinary power of vision for the time, and sometimes without robbing us of that.
What we call our physical consciousness is not a fixed and determinate amount which has always been the same. It has gradually grown to be what it is, and many things which were formerly within its purview have now passed below it-- or more accurately, it has so developed itself as to rise above them. Its level is gradually rising; our descendants will be able to see colours which at present are invisible to us-- higher, purer and more delicate colours. Whether they will at the same time lose the possibility of appreciating some of the coarsest of the colours which we now know, is uncertain.
British Virgin Islands 1 by Allison L. Williams Hill
Delirium shifts the place of this consciousness, and often altogether shuts out from us the everyday world which we know, giving us sometimes in its place memories of our past-- not only of the past of this life but of the longer-forgotten part of the human race. Such sight as delirium gives often includes the power to see the sufferer's own thought-forms, or those of others, and sometimes also to see the astral and etheric creatures which are around him. In the case of delirium-tremens, for example, the snakes and other horrors are almost invariably creatures of low type which are feasting upon the fumes of alcohol exuding from the body of the drunkard.