A SURVEY OF THE PROBLEM OF VITALISM 425 



mechanics. It would, even in practice, be quite easy to arrange 

 the balls in such positions that stimuli arriving from three 

 different named directions should all produce the same result, 

 whereas two stimuli arriving in closely similar directions should 

 produce widely different results. There is nothing at all in- 

 conceivable about it, either in theory or practice ; it is simply 

 a question of the prior arrangement of the balls, or autrement 

 dita. question of the elaboration and complexity of the machinery 

 interposed between the stimulus and its ultimate effect. 

 Vitalistic explanation : The incoming ball doubtless sets up a 

 normal series of impacts which without interference would 

 proceed to a normal result. But in order to explain the identity 

 of result from a varying stimulus, we assume that one, or more, 

 balls begin to move by a process of spiritual inspiration, and so 

 nicely do they calculate the effects of their motion that after a 

 series of impacts the new motion will become added to the 

 pre-existing normal motion to produce just the precise result 

 expected. 



Now, if it be alleged that the mechanistic proposition is 

 difficult to imagine, it may be replied that the vitalistic proposi- 

 tion is impossible to imagine. For the mechanistic proposition, 

 the only requirement is a machine of enormous elaboration and 

 complexity, just such a machine as the developed brain appears 

 morphologically to be. For the vitalistic proposition, no 

 machine is necessary at all, and the machine which we actually 

 find for the transmission of impulses appears to be a magnificent 

 redundancy. The effect is achieved by immediate creation of 

 spontaneous motion, the precise direction of which is calculated 

 to a nicety. This is a conception unknown to science : it has 

 about it a strange ring of mediaeval mythology : it belongs to 

 that spiritual type of " explanation " which has ever receded 

 before the advance of science, and whose long series of defeats 

 has never in history been broken by a single victory. 



The billiard-ball analogy errs, of course, in its immeasurable 

 simplicity when compared with the structure of the brain. 

 Supposing I were to cover this page with little dots of ink, and 

 supposing the page itself were magnified and extended until it 

 covered the entire surface of the earth, still blackened with 

 innumerable dots running in long strands or meeting in complex 

 reticulations, we should have a somewhat more accurate analogy 

 with the nervous system and its component physiological units. 



