When mineral evolution is completed, the life has withdrawn itself again into the astral world, but bearing with it all the results obtained through its experiences in the physical.  At this stage it ensouls vegetable forms, and begins to show itself much more clearly as what we commonly call life—­plant-life of all kinds; and at a yet later stage of its development it leaves the vegetable kingdom and ensouls the animal kingdom.  The attainment of this level is the sign that it has withdrawn itself still further, and is now working from the lower mental world.  In order to work in physical matter from that mental world it must operate through the intervening astral matter; and that astral matter is now no longer part of the garment of the group-soul as a whole, but is the individual astral body of the animal concerned, as will be later explained.

In each of these kingdoms it not only passes a period of time which is to our ideas almost incredibly long, but it also goes through a definite course of evolution, beginning from the lower manifestations of that kingdom and ending with the highest.  In the vegetable kingdom, for example, the life-force might commence its career by occupying grasses or mosses and end it by ensouling magnificent forest trees.  In the animal kingdom it might commence with mosquitoes or with animalculae, and might end with the finest specimens of the mammalia.

The whole process is one of steady evolution from lower forms to higher, from the simpler to the more complex.  But what is evolving is not primarily the form, but the life within it.  The forms also evolve and grow better as time passes; but this is in order that they may be appropriate vehicles for more and more advanced waves of life.  When the life has reached the highest level possible in the animal kingdom, it may then pass on into the human kingdom, under conditions which will presently be explained.

The outpouring leaves one kingdom and passes to another, so that if we had to deal with only one wave of this outpouring we could have in existence only one kingdom at a time.  But the Deity sends out a constant succession of these waves, so that at any given time we find a number of them simultaneously in operation.  We ourselves represent one such wave; but we find evolving alongside us another wave which ensouls the animal kingdom—­a wave which came out from the Deity one stage later than we did.  We find also the vegetable kingdom, which represents a third wave, and the mineral kingdom, which represents a fourth; and occultists know of the existence all round us of three elemental kingdoms, which represent the fifth, sixth and seventh waves.  All these, however, are successive ripples of the same great outpouring from the Second Aspect of the Deity.

We have here, then, a scheme of evolution in which the divine Life involves itself more and more deeply in matter, in order that through that matter it may receive vibrations which could not otherwise affect it—­impacts from without, which by degrees arouse within it rates of undulation corresponding to their own, so that it learns to respond to them.  Later on it learns of itself to generate these rates of undulation, and so becomes a being possessed of spiritual powers.