To sum up: In the actual state of our knowledge it is impossible to give a complete, total, absolute, final explanation of the observed phenomena. The Spiritualistic hypothesis ought not to be dismissed. Still, we may admit the survival of the soul without necessarily admitting a physical communication between the dead and the living. But then all the observed facts leading up to the affirmation of this communication are worthy of the most serious attention of the philosopher.
One of the chief difficulties in the way of these communications seems to be the condition itself of the soul freed from bodily senses. It would have other ways of perceiving. It would not see, hear, touch. How then can it enter into relation with our senses?
There is a whole problem in that which is not to be neglected in the study of any psychical manifestations whatever.
We take our ideas to be realities. This is a mistake. For example, to our senses the air is not a solid body; we pass through it without effort, while we cannot pass through an iron door. The converse is true of electricity: it passes through iron, and finds the air to be a solid impassible body. To the electrician, a wire is a canal leading electricity across the solid rock of the air. Glass is opaque to electricity and transparent to magnetism. The flesh is transparent to the X-rays, while glass is opaque, etc.
We feel the need of explaining everything, and we are driven to admit only the phenomena of which we have had an explanation; but that does not prove that our explanations are valid. Thus for example, if some one had affirmed the possibility of instantaneous communication between Paris and London, before the invention of the telegraph, people would have regarded the assertion as utopian. Later it would not have been admitted, except on condition of the existence of a wire between the two stations, and any communication without the medium of an electric wire would have been declared impossible. Now that we have wireless telegraphy we can apply this discovery to the explanation of the phenomena of telepathy. But it is not yet proved that this explanation is the true one.
Why do we wish to explain these phenomena at all hazards? Because we naïvely imagine that we are able to do so in the present state of our knowledge.
The physiologists who claim to see daylight in this matter are like Ptolemy persisting in accounting for the movements of the heavenly bodies by holding to the idea of the immobility of the earth; or Galileo explaining the attraction of amber by the rarefaction of the surrounding air; or Lavoisier seeking (with the common people) the origin of aërolites in thunder storms or denying their existence; or Galvani, who saw in his frogs a special organic electricity. I put my physiologists in good company, surely, and they have nothing of which to complain. But who does not feel that this natural propensity to explain everything is not justified, that science progresses from age to age, that what is not known to-day will be known later, and that we ought sometimes to know how to wait?
The phenomena of which we are speaking are manifestations of the universal dynamism, with which our five senses put us very imperfectly in relation. We live in the midst of an unexplored world, in which the psychical forces play a role still very insufficiently investigated.
These forces are of a class superior to the forces usually analyzed in mechanics, in physics, in chemistry: they are of the psychical order, have in them something vital and a kind of mentality. They confirm what we know from other sources,—that the purely mechanical explanation of nature is insufficient and that there is in the universe something else than so-called matter. It is not matter that rules the world: it is a dynamic and psychic element.