Each definite thought produces a double effect--a radiating vibration
and a floating form. The thought itself appears first to clairvoyant
sight as a vibration in the mental body, and this may be either simple
or complex. If the thought itself is absolutely simple, there is only
the one rate of vibration, and only one type of mental matter will be
strongly affected. The mental body is composed of matter of several
degrees of density, which we commonly arrange in classes according to
the sub-planes. Of each of these we have many sub-divisions, and if we
typify these by drawing horizontal lines to indicate the different
degrees of density, there is another arrangement which we might
symbolise by drawing perpendicular lines at right angles to the others,
to denote types which differ in quality as well as in density. There are
thus many varieties of this mental matter, and it is found that each one
of these has its own especial and appropriate rate of vibration, to
which it seems most accustomed, so that it very readily responds to it,
and tends to return to it as soon as possible when it has been forced
away from it by some strong rush of thought or feeling. When a sudden
wave of some emotion sweeps over a man, for example, his astral body is
thrown into violent agitation, and its original colours are or the time
almost obscured by the flush of carmine, of blue, or of scarlet which
corresponds with the rate of vibration of that particular emotion. This
change is only temporary; it passes off in a few seconds, and the astral
body rapidly resumes its usual condition. Yet every such rush of feeling
produces a permanent effect: it always adds a little of its hue to the
normal colouring of the astral body, so that every time that the man
yields himself to a certain emotion it becomes easier for him to yield
himself to it again, because his astral body is getting into the habit
of vibrating at that especial rate.
The majority of human thoughts, however, are by no means simple.
Absolutely pure affection of course exists; but we very often find it
tinged with pride or with selfishness, with jealousy or with animal
passion. This means that at least two separate vibrations appear both in
the mental and astral bodies--frequently more than two. The radiating
vibration, therefore, will be a complex one, and the resultant
thought-form will show several colours instead of only one.