The divine Life pours itself into matter from above, and its whole course may be thought of in two stages--the gradual assumption of grosser and grosser matter, and then the gradual casting off again of the vehicles which have been assumed. The earliest level upon which its vehicles can be scientifically observed is the mental--the fifth counting from the finer to the grosser, the first on which there are separated globes. In practical study it is found convenient to divide this mental world into two parts, which we call the higher and the lower according to the degree of density of their matter. The higher consists of the three finer subdivisions of mental matter; the lower part of the other four. When the outpouring reaches the higher mental world it draws together the ethereal elements there, combines them into what at that level correspond to substances and of these substances builds forms which it inhabits. We call this the first elemental kingdom. After a long period of evolution through different forms at that level, the wave of life, which is all the time pressing steadily downwards, learns to identify itself so fully with those forms that, instead of occupying them and withdrawing from them periodically, it is able to hold them permanently and make them part of itself, so that now from that level it can proceed to the temporary occupation of forms at a still lower level. When it reaches this stage we call it the second elemental kingdom, the ensouling life of which resides upon the higher mental levels, while the vehicles through which it manifests are on the lower. After another vast period of similar length, it is found that the downward pressure has caused this process to repeat itself; once more the life has identified itself with its forms, and has taken up its residence upon the lower mental levels, so that it is capable of ensouling bodies in the astral world. At this stage we call it the third elemental kingdom. We speak of all these forms as finer or grosser relatively to one another, but all of them are almost infinitely finer than any with which we are acquainted in the physical world. Each of these three is a kingdom of Nature, as varied in the manifestations of its different forms of life as is the animal or vegetable kingdom which we know. After a long period spent in ensouling the forms of the third of these elemental kingdoms it identifies itself with them in turn, and so is able to ensoul the etheric part of the mineral kingdom, and becomes the life which vivifies that--for there is a life in the mineral kingdom just as much as in the vegetable or the animal, although it is in conditions where it cannot manifest so freely. In the course of the mineral evolution the downward pressure causes it to identify itself in the same way with the etheric matter of the physical world, and from that to ensoul the denser matter of such minerals as are perceptible to our senses.