The Inner Life, v. II/Third Section/V
THOUGHT AND ELEMENTAL ESSENCE
Elemental essence when moulded by thought adopts a certain colour — a colour which is expressive of the nature of the thought or feeling. Of course all that this really means is that the essence composing the thought-form is for the time compelled to vibrate at a certain definite rate by the thought which is ensouling it. The evolution of the elemental essence is to learn to respond to all possible rates of undulation; when therefore a thought holds it for a time vibrating at a certain rate, it is helped to this extent, that it has now become habituated to that particular rate of oscillation, so that next time it comes within reach of a similar one, it will respond to it much more readily than before.
Presently those atoms of essence, having passed back again into the general mass, will be caught up again by some other thought, and will then have to swing at some totally different rate, and so will evolve a little further by acquiring the capacity to respond to the second type of undulation. So by slow degrees the thoughts, not only of man, but also of nature-spirits and devas, and even of animals so far as they do think, are evolving the elemental essence which surrounds them — slowly teaching here a few atoms, and there a few atoms, to respond to this or that different rate of oscillation, until at last a stage will be reached when all the particles of the essence shall be ready to answer at any moment to any possible rate of vibration, and that will be the completion of their evolution.
It is for this reason that the occultist avoids when possible the destruction of an artificial elemental, even when it is of evil character, preferring rather to defend himself or others against it by using the protection of a shell. It is possible to dissipate an artificial elemental instantly by an exertion of will-power, just as it is possible on the physical plane to kill a poisonous snake in order that it may do no further harm; but neither course of action would commend itself to an occultist, except in very unusual circumstances.
Whether the thought ensouling it is evil or good makes no difference whatever to the essence; all that is required for its development is to be used by thought of some kind. The difference between the good and the evil would be shown by the quality of essence which it affected, the evil thought or desire needing for its appropriate expression the coarser or denser matter, while the higher thought would require correspondingly finer and more rapidly vibrating matter for its covering. There are plenty of undeveloped people always thinking the coarser lower thoughts, and their very ignorance and grossness are made use of by the great Law as evolutionary forces to help on a certain stage of the work that is to be done. It is for us, who have learnt a little more than they, to strive ever to think the high and holy thoughts which cause the evolution of a finer kind of elemental matter, and so to work in a field where at present the labourers are far too few.