By the first faint gleams of the light of hidden wisdom, which are beginning to dawn upon his mind, he now perceives that responsibility does not end upon the plane of earth, but extends into the aerial regions of that inner world where his thoughts are no longer secret, and where they affect the astral currents, acting for the good or detriment of others to almost infinite extent; that he may act upon the ambient atmospheres, not only of the outer but inner planes of life, like a plant of poisonous exhalations, if his thoughts be not pure and good; peopling _unseen_ space with the outcome of a debased mind, in the shape of hideous and maleficent creatures. He becomes responsible, therefore, for the consequences of his mental actions and thought-life, as well as those actions carefully prepared to pass unchallenged before this world's gaze. Diving into the unseen by the light of the new spiritual knowledge now radiating into all minds, we learn that there are three degrees of life in man, the material, the aerial, and the ethereal, corresponding to body, soul, and spirit; and that there are three corresponding planes of existence inhabited by beings suited to them. The subject of our paper will limit us at present to the aerial, or soul-plane--the next contiguous, or astral world. The beings that more especially live in this realm of the soul, have by common consent been termed _elementals_. Nature in illimitable space teems with life in forms ethereal, evanescent as thought itself, or more objectively condensed and solidified, according to the inherent attraction which holds them together; enduring according to the force, energy, or power which gave them birth; intelligent, or non-intelligent, from the same source, which is mental. These spirits of the soul-world are possessed of aerial bodies, and their world has its own firmament, its own atmosphere and conditions of existence, its own objects, scenes, habitations. Yet their world and the world of man intermingle, interpenetrate, and "throw their shadows upon each other," says Paracelsus. Again, he says: "As there are in our world water and fire, harmonies and contrasts, visible bodies and invisible essences, likewise these beings are varied in their constitution, and have their own peculiarities, for which human beings have no comprehension."