Science, whose aim is to understand nature, must 

 set out with the assurance that nature is under- 

 standable. 



VON HELMHOLTZ. 



Is there any phenomenon which works upon 

 neither our natural senses, nor upon their ex- 

 tensions, our present-day instruments and ap- 

 paratus? Then, unless it be out of relation with 

 things, must it still be bound up with other phe- 

 nomena which do work upon our senses or our 

 instruments. Thus it must sooner or later be- 

 come perceptible to us. 



OTTO WIENER, Die Enveiterung unserer Sinne. 



