358 THE POPULAR SCIENCE MONTHLY, 



soon as its work has been accomplished. And, if the scientific archi- 

 tects are so captivated with the scaffolding that they insist upon main- 

 taining it intact, its eventual demolition is none the less sure in the 

 progress of observation and experiment. Facts supply the ictus calcis 

 which the theorist refuses to administer. 



Du Bois-Reymond's proposition is nothing less than this, that nat- 

 ural science is constrained, by the law of all its methods, to exhibit 

 the arbitrary scaffolding of the intellect as the real nature of the uni- 

 verse. He not only confounds the scaffolding of his intellect with its 

 own structure, but he confounds this scaffolding with the structure of 

 Nature. He mistakes the beams of his temporary platform for the 

 rafters of the permanent edifice ; the arbitrary masses of his mathe- 

 matical calculations (the " atoms ") for bricks of Nature's building ; 

 and the ropes of his scientific tackling (the " forces ") for the ingen- 

 erate energy of the Universe. There are, it is true, passages in Du 

 Bois-Reymond's lecture which may be construed as a virtual dis- 

 claimer of this, but his assumption that the limits of mathematical 

 reasoning about atoms and their constant central forces are the irre- 

 movable bounds of all possible knowledge respecting physical phe- 

 nomena, and the emphatic "Ignoramus — Ignorabimus" with which 

 he concludes his lecture, utterly invalidate the disclaimer. He forgets 

 that the framework on which he and his compeers have thus far been 

 stationed is by no means the only scaffolding that can be devised. 

 The spectroscope has convinced the chemist that a chemical analysis 

 can be effected otherwise than by mixing substances in a testing-tube, 

 and that he can react upon the gas of a distant comet as well as upon 

 the hydrogen in the water which flows from a stop-cock in his labora- 

 tory. Modern analysis has shown that the limits of mathematical in- 

 sight, which the synthetical geometrician supposed to be absolute, 

 may be transcended indefinitely ; and Gauss's and Hamilton's new 

 conception which is now expanding into the calculus of operations, or 

 calculus of quaternions, is opening theoretical vistas which, even to 

 the analyst of modern times, seem next to illimitable. It is true that 

 no mathematical wings will ever carry us into the regions of the " Ab- 

 solute," and no spectroscopic vision will discern the indelible spectral 

 bands of the " thing per se ; " but, before we indulge in any lamenta- 

 tions over this fact, it may be well to examine the livery of the mes- 

 senger who brings us the wonderful intelligence of the existence of 

 these entities without all possible relation to the intellect, and to in- 

 quire of him how he became possessed of his message. 



I must not be understood as asserting or intimating that our 

 knowledge can ever be other than asymptotic to the endless and 

 boundless fact of the universe. But there is a dogmatism of igno- 

 rance which is no less audacious than the dogmatism of sciolistic knowl- 

 edge. The " Ignoramus — Ignorabimus " at the close of Du Bois-Rey- 

 mond's lecture is at least as presumptuous as the pretended omnis- 



