PROGRESS OF PSYCHOLOGY. 447 



the centres of sight and speech, for instance, involve 

 an equivalent loss, temporary or permanent, of words 

 and ideas." * The close parallelism of the two sets 

 of facts is certain; the difficulty is how to conceive 

 of their relation. 



(6) With the advance of physiological analysis, 

 a materialistic school found confidence to claim psy- 

 chology as entirely a branch of physiology. In crude 

 expression, it was said that as the liver secrets bile, 

 so the brain secretes thought ; or, that as the collisions 

 in a swarm of meteors engender heat and light, so 

 the whirlpool of molecules within a ganglion has part 

 of its energy expressed as consciousness. 



This conclusion includes two distinct assump- 

 tions: (1) that material agency is the only real 

 condition of protoplasmic metabolism (or bodily 

 life), and so likewise of consciousness or mental life, 

 and (2) that physiological interpretations are suffi- 

 cient for mental occurrences. The first assumption 

 is a metaphysical dream involving the fallacy of 

 " postulating mechanism as the substratum and not as 

 the conceptional expression of certain groups of sense- 

 impressions " (Pearson) ; the second assumption has 

 not been justified by any success. No one has suc- 

 ceeded in giving a physiological interpretation of 

 any mental process; though the physical conditions 

 attendant on many mental processes are known, the 

 relations between the two have not been apprehended. 



A quotation from Dr. G. F. Stout's Analytic Psy- 

 chology (1896) may be permitted here: 



" Those who deny agency to consciousness, finding 

 that mental events occur which are not immediately 



* Prof. James Ward, Naturalism and Agnosticism, 1899, 

 Vol. I. p. 10. 



