all natural laws were overthrown by the fact, and that in the fact itself no kind of law or order was to be perceived. This case lies before us here. The laws of gravitation, of electricity, of light, and of heat are altogether, as we are assured, of a purely hypothetical validity; they have authority as long as the inexplicable spiritualistic something does not cross them. In this something itself, however, there is to be perceived no sort of law except, at the most, that it is hooked to the heels of certain individuals, the so-called mediums. An authority which asserts this demands more than a scientific authority has ever demanded; it demands that natural Science shall abandon the presupposition of a universal causality, the presupposition upon which all the methods of her investigation rest, and without which an establishment of facts or even of laws of occurrence could never be spoken of.
You will agree with me that this would not be the place to enter upon any long discussion of the origin of the law of causation. You will also probably admit that the most favorable assumption which we could make for spiritualism would be that of its purely empirical origin. Empirical laws can at any time be refuted by other empirical laws. How now, with this premise, is the trustworthiness of a universal causality related to the trustworthiness of the spiritualistic phenomena? On the one side stands the authority of the whole history of science, the totality of all known natural laws, which have not only been discovered under the presupposition of a universal causality, but have also without exception confirmed the same; on the other side stands the authority of a few certainly most eminent naturalists, who, in all which they have discovered in the absence of mediumistic influences, have contributed their part to the confirmation of that most general result of natural investigation, but who now in this one point, under a constellation of circumstances which make exact observation difficult in the highest degree, announce the discovery that causality has a flaw and that we must consequently abandon our former view of nature.
I have spoken of the unfavorable constellations under which the spiritualistic phenomena were observed, and, since you might question the warrant of this expression, I must give it a somewhat better basis. I call the constellations unfavorable for observations or experiments, when the observer can not freely manage his senses and his instruments. You would yourself probably call it an unjust demand if a physicist were asked to observe the oscillations of a magnet through a key-hole or an astronomer to take a cellar for his observatory. Yet the observers of spiritualistic phenomena must content themselves with equally unfavorable conditions. The first condition of the success of the experiments is that all persons present shall lay their hands together upon a table and that no observer shall be outside the circle. Thereby a great part of the field of operation is withdrawn from the
