In the same way might not those persons deceive themselves who, in order to escape at any cost the necessity of the hypothesis of spiritistic entities, should insist with a too persistent predilection upon the animistic hypothesis, even when this would be found insufficient to explain all mediumistic manifestations? Might it not be true that, like electric and magnetic phenomena, which are in close interchangeable connection, and frequently appear to us inseparable, animistic and spiritistic phenomena have a common bond? And let us well note that a single fact, inexplicable by the animistic hypothesis and explicable by the spiritistic hypothesis, would suffice to confer upon the latter that degree of scientific value which up to the present time has been so energetically denied to it, just as the discovery of a secondary phenomenon, that of the polarization of light, sufficed to make Fresnel reject the Newtonian theory of emission and admit that of undulation.
Did we obtain, during the course of our ten séances with Eusapia, the one fact which is enough to make the spiritistic hypothesis necessarily take precedence of all others?
It is impossible to reply categorically to this question because it is not possible, and never will be, to have a scientific proof of the identity of the beings who manifest themselves.
The fact that I hear, that I see, that I touch a phantom; that I recognize in it the form and the attitude of persons whom I have known and whom the medium has neither known nor of whom she has even heard the names; that I have the most lively and affecting testimony to the presence of this ephemeral apparition,—all that will not be sufficient to constitute the scientific fact which none can refute, and which shall be worthy to remain in the annals of science along with the experiments of Torricelli, Archimedes and Galvani. It will always be possible to imagine an unknown mechanism by the aid of which elemental substance and power may be drawn from the medium and the sitters and combined in such a way as to produce the indicated effects. It will always be possible to find in the special aptitudes of the medium, in the thought of the sitters, and even in their attitude of expectant attention, the cause of the human origin of the phenomena. It will always be possible to unearth from the arsenal of the attacks made upon these studies during the last fifty years, some generic or specific argument, either ad rem or ad hominem, while ignoring or feigning to ignore the refutation of the argument which has already been made.
The question, then, reduces itself at once to an individual study of cases either directly observed or obtained from some sure hand, in order on the one hand, to create a personal conviction capable of resisting the scathing ridicule of the sceptics, and, on the other hand, to prepare public opinion to admit the truth of cases observed by persons worthy of credence.
With regard to the first of these, the illustrious experimenter Sidgwick, has already said that no fact or case exists capable of convincing everybody, but that each one, by patiently and calmly observing, may find such fact or case as will suffice to establish his own conviction. I may say that for myself such a case exists. I need only refer to the phenomena in which I have personally participated in the séances with Eusapia.
With regard to the second point I could say much, but that would lead me beyond the subject matter and the limits of this study.
On the one hand, we have the universal belief in the objective existence of a world unknown to us in our normal state; that faith (the basis of all religions) in a future life where the injustices of this one will be atoned for and where we shall be confronted with the good or evil deeds that we have done on earth; that uninterrupted tradition of systematic or spontaneous observances and rituals, thanks to which man is constantly kept in relation more or less with that unknown world.
On the other hand, we have the sceptical and disheartening negation of systems of pessimistic philosophy and of atheism, a negation which takes its rise in the absence of positive proofs of the survival of the soul; the ever more and more marked tendency of science toward a monistic interpretation of the enigma of human life; and the belief that all the known phenomena of life appear only in connection with special organs.
In order to decide in so abstruse a matter as this, mediumistic experiments do not suffice; everyone may draw from these as much of credence or of incredulity as he may need in order to resolve his doubts in one way or another; but he will never divest himself of the substratum of temperamental tendencies which the more or less scientific education of his mind or the more or less mystical inclinations of his nature shall have developed in him.