We come now to consider the second effect produced when a man uses his mental body in thinking, viz., the formation of thought forms. As we have seen, a thought gives rise to a set of vibrations in the matter of the mental body. Under this impulse the mental body throws off a vibrating portion of itself shaped by the nature of the vibrations, much in the way that fine particles laid on a disc are thrown into a form when the disc is made to vibrate to a musical note.
The mental matter thus thrown off gathers from the surrounding atmosphere elemental essence of the mental world [i.e.,, of the Second Elemental Kingdom] of the appropriate type, and sets that essence into vibration in harmony with its own rate. Thus is generated a thought form pure and simple. Such a mental thought-form resembles an astral or emotional form, but it is far more radiant and more brilliantly coloured, is stronger and more lasting, and more fully vitalised.
A graphic description of the effect of thought is as follows. “These [mental] vibrations, which shape the matter of the plane into thought-forms, give rise from their swiftness and subtlety to the most exquisite and constantly changing colours, waves of varying shades like the rainbow hues in mother-of-pearl, etherialised and brightened to an indescribable extent, sweeping over and through every form so that each presents a harmony of rippling, living, luminous, delicate colours, including many not even known on earth. Words can give no idea of the exquisite beauty and radiance shown in combinations of this subtle matter, instinct with life and motion. Every seer has witnessed it, Hindu, Buddhist, Christian, speaks in rapturous terms of its glorious beauty and ever confesses his utter inability to describe it; words seem but to coarsen and deprave it however deftly the praise.”
A thought form is a temporary living entity of intense activity animated by the one idea that generated it. If made of the finer kinds of matter, it will be of great power and energy, and may be used as a most potent agency when directed by a strong and steady will. Into the details of such use we shall enter later. The elemental essence is a strange semi-intelligent life which surrounds us, vivifying matter of the mental plane. It responds readily to the influence of human thought so that every impulse sent out from the mental body of a man immediately clothes itself in a temporary vehicle of this essence.
It is, in fact, even more instantaneously sensitive, if that be possible, to the action of thought than is astral elemental essence. But mental elemental essence differs greatly from astral elemental essence; it is a whole chain behind the other, and, therefore, the force in it cannot work quite in the same concentrated way. It is trying to deal with, for it is largely responsible for our wandering thoughts, as it darts constantly from one thing to another.
***From Arthur E. Powell – The Mental Body