THE FOURTH DIMENSION. 



der which they will or will not succeed. When all the preparations 

 in a spiritualistic stance have been properly made, but nothing takes 

 place, the beautiful excuse is always forthcoming that the " spirits 

 were not willing," that there were "too many incredulous persons 

 present," and so forth. Fortunately, in physical experiments these 

 pretexts are not necessary. By the path of experiment, and not by 

 that of transcendental speculation, physics has thus made incredible 

 progress and has piled new knowledge strata on strata upon the 

 old. Accordingly, the prospect is left that the mysteries which the 

 conditions and properties of the human soul still present can be 

 solved more and more by the methods of scientific experiment. To 

 this end, however, it is especially necessary that the physio-psycho- 

 logical experiments in question should only be performed by men 

 who possess the critical eye of inquiry, who are free from the dan- 

 gers of self-illusion, and who are competent to keep apart from their 

 experiments all superstition and deception. The history of natural 

 science clearly teaches that it is only by this road that man can ar- 

 rive at certain and well-established knowledge. If, therefore, there 

 really is behind such phenomena as mind-reading, telepathy, and 

 similar psychical phenomena, something besides humbug and self- 

 illusion, what we have to do is to study privately and carefully by 

 serious experiments the success or non-success of such phenomena, 

 and not allow ourselves to be influenced by the public and dramatic 

 performances of psychical artists, like Cumberland and his ilk. 



The high eminence on which the knowledge and civilisation of 

 humanity now stands was not reached by the thoughtless employ- 

 ment of fanciful ideas, nor by recourse to four-dimensional worlds, 

 but by hard, serious labor, and slow, unceasing research. Let all men 

 of science, therefore, band themselves together and oppose a solid 

 front to methods that explain everything that is now mysterious to 

 us by the interference of independent spirits. For these methods, 

 owing to the fact that they can explain everything, explain nothing, 

 and thus oppose dangerous obstacles to the progress of real research, 

 to which we owe the beautiful temple of modern knowledge. 



