ADDRESS. 28 



and of dead matter under a common formula touch the evidence for the 

 atomic theory. The question as to whether matter consists of elements 

 capable of independent motion is prior to and independent of the 

 further questions as to what these elements are, and whether they are 

 alive or dead. 



The physicist, if he keeps to his business, asserts, as the bases of 

 the atomic theory, nothing more than that he who declines to admit 

 that matter consists of separate moving parts must regard many of the 

 simplest phenomena as irreconcilable and unintelligible, in spite of the 

 fact that means of reconciling them are known to everybody, in spite 

 of the fact that the reconciling theoiy gives a general correlation of an 

 enormous number of phenomena in every branch of science, and that the 

 outstanding difficulties are connected, not so much with the fundamental 

 hypotheses that matter is composed of distinguishable entities which are 

 capable of separate motions as with the much more difficult problem of 

 what these entities are. 



On these grounds the physicist may believe that, though he cannot 

 handle or see them, the atoms and molecules are as real as the ice 

 crystals in a cirrus cloud which he cannot reach ; as real as the unseen 

 members of a meteoric swarm whose death-glow is lost in the sunshine, or 

 which sweep past us, unentangled, in the night. 



If the confidence that his methods are weapons with which he can 

 light his way to the truth were taken from the scientific explorer, the 

 paralysis which overcomes those who believe that they are engaged in a 

 hopeless task would fall upon him. 



Physiology has specially flourished since physiologists have believed 

 that it is possible to master the physics and chemistry of the framework 

 of living things, and since they have abandoned the attitude of those who 

 placed in the foreground the doctrine of the vital force. To supporters of 

 that doctrine the principle of life was not a hidden directing power which 

 could perhaps whisper an order that the flood-gates of reservoirs of energy 

 should now be opened and now closed, and could, at the most, work only 

 under immutable conditions to which the living and the dead must alike 

 submit. On the contrary, their vital force pervaded the organism in all 

 its parts. It was an active and energetic opponent of the laws of physics 

 and chemistry. It maintained its own existence not by obeying but by 

 defying them ; and though destined to be finally overcome in the separate 

 campaigns of which each individual living creature is the scene, yet like 

 some guerilla chieftain it was defeated here only to reappear there with 

 unabated confidence and apparently undiminished force. 



This attitude of mind checked the advance of knowledge. Difficulty 

 could be evaded by a verbal formula of explanation which in fact ex- 

 plained nothing. If the mechanical, or physical, or chemical causes of a 

 phenomenon did not lie obviously upon the surface, the investigator was 

 tempted to forego the toil of searching for them below ; it was easier to 

 say that the vital force was the cause of the discrepancy, and that it was 



