2. The universal cosmic fluid is, as has been demonstrated, elementary primitive matter, of which the modifications and transformations constitute the innumerable varieties of the bodies of nature (Chap. X). So far as the elementary universal principle is concerned, it offers two distinct states; that of etherealization, or imponderability, that one can consider as the primitive and normal state, and that of materialization, or ponderability, which is in some sort only consecutive. The intermediary point is that of the transformation of the fluid into tangible matter; but there still is no sudden transition, for one can consider our imponderable fluids as a boundary between the two states (chap. IV, from n° 10 on).
Each one of these two states gives place necessarily to special phenomena. To the second belong those of the visible world, and to the first those of the invisible one. Those called material phenomena are, properly speaking, in the domain of science. The solution of the others, designated spiritual or psychical phenomena, because they are allied more especially to the existence of spirits, is among the prerogatives of Spiritism. But, as spiritual and material life are in incessant contact, the phenomena of these two orders are presented often simultaneously. Man, in a state of incarnation, can have only the perception of the physical phenomena which are connected with the material life. Those which belong to the exclusive domain of spiritual life escape the eye of the material senses, and can be perceived only in the spiritual state. *
*The name psychical phenomena expresses the idea better than spiritual does, as these phenomena rest upon the properties and attributes of the soul, or rather on the perispiritual fluids, which are inseparable from the soul. This qualification attaches them more intimately to the order of natural facts, regulated by laws. One can then admit them as psychical effects without allowing them the title of miracles.