THE FAILURE OF SCIENTIFIC MATERIALISM. 595 



tion of the phenomena in a system of moving mass-points is the 

 end which the theory of Nature is trying to reach. If this princi- 

 ple falls, and we have seen that it must fall, the ignorabimus falls 

 with it, and science again has free course. 



I do not believe that you will accept this result with surprise, 

 for, if I can judge from my own experience, hardly a naturalist 

 has seriously believed in the ignorabimus unless he has failed to 

 make clear to himself in what point that in it which is untenable 

 lies. But the gain to the negative criticism of the mechanical 

 theory of the world accruing from the formal laying of that 

 menacing specter may be of some value to many thinkers who 

 have nothing to oppose to the inevitable logic of Du Bois-Rey- 

 mond's demonstration. 



What is here laid down for the sake of clearness, in respect to 

 these particular discussions, has, however, a considerably wider 

 bearing. The refutation of the mechanical construction of the 

 universe touches the basis of the whole materialistic theory of the 

 world, the terms being taken in the scientific sense. It appears a 

 vain undertaking, with ultimate failure decreed to every earnest 

 effort, to interpret known physical phenomena mechanically ; 

 hence the conclusion is unavoidable that the attempt can still 

 less succeed with the vastly more complicated phenomena of 

 organic life. The same contradiction of principle forces itself 

 upon us here, and the supposition that all natural phenomena 

 can be traced back primarily to mechanical factors can not even 

 be designated an available working hypothesis. It is a mere 

 error. 



The following fact bears most plainly against this error : Me- 

 chanical equations all have the property of permitting the ex- 

 change of the sign of time that is, the theoretically perfected 

 mechanical processes can as well go backward as forward. In a 

 purely mechanical world there are therefore no earlier and later 

 in the sense of our world : the tree might be changed into a twig 

 or a seed, the butterfly to a caterpillar, and the old man to a child. 

 The mechanical theory has no explanation of the fact that this 

 does not take place, and, on account of the property of mechan- 

 ical equations which we have mentioned, can have none. The 

 actual ir reversibility of real phenomena also demonstrates the 

 existence of processes that are not representable by mechanical 

 equations ; and with this the condemnation of scientific material- 

 ism is pronounced. 



It thus appears to result certainly from these considerations 

 that we shall have finally to renounce the hope of explaining the 

 physical world intuitively by tracing its phenomena back to a 

 mechanics of the atoms. But, I hear it said, if the conception of 

 moving atoms is taken away from us, what means is left of form- 



