189S] MR HERBERT SPENCER'S BIOLOGY 381 



failure of the controversialists to distinguish carefully between 

 noumenal and phenomenal causation. 



The question may now be asked whether Mr Spencer is well- 

 advised in attempting to comprise under one definition of life (1) 

 certain fundamental attributes of living matter and (2) sundry com- 

 plex results of evolution. Is not the correspondence between life 

 and its circumstances rather the result of the interaction of vital 

 factors, under the influence of the environment, than a primary 

 characteristic of the vital factor itself ? And if it be true that the 

 degree of life varies as the degree of correspondence (which is open 

 to question, since it is rather struggle than attainment which calls 

 forth most strenuous vital energy) it is surely aggregate results, 

 rather than fundamental properties, that we have in mind. If a 

 unit must be selected, the cell, not the metazoon or analogous 

 plant-complex, seems to be the more appropriate. But it is per- 

 haps more profitable to fix attention, not on the variable unit, but 

 on the common substance — protoplasm ; to say that protoplasm has 

 certain specified metabolic or other properties, that the processes 

 carried on in virtue of these properties are what we comprise under 

 the term life, and that evolution is the outcome under certain given 

 conditions. 



If Mr Spencer reply that the outcome in evolution is itself a 

 fundamental attribute of life, it is difficult to see, in view of his 

 position with regard to the dynamic element, on what a priori 

 ground he criticises the hypothesis of determinate evolution — the 

 orthogenesis of Eimer. To argue that the evidence of such de- 

 terminate evolution is insufficient is a perfectly legitimate scientific 

 position. But Mr Spencer goes further. He says : " The assertion 

 that evolution takes definitely-directed lines is accompanied by no 

 indication of the reasons why particular lines are followed rather 

 than others. In short, we are simply taken a step back, and for 

 further interpretation referred to a cause said to be adequate but 

 the operations of which we are to imagine as best we may." If, 

 however, we are to believe in a dynamic element in life, itself 

 inexplicable, and if the outcome in evolution is in itself a funda- 

 mental attribute of life, it is difficult to see why the inexplicable 

 determinate tendency should not be part and parcel of the in- 

 explicable operation of the dynamic element. But if we regard 

 evolution as the result of the complex interaction of vital factors, 

 then we may fairly demand an explanation of the manner in which 

 such interaction can give rise to orthogenesis. 



It would be unprofitable (even if space permitted) to discuss at 

 any length the pros and cons of what Mr Spencer terms direct 

 equilibration. He is deeply committed to the inheritance of ac- 

 quired modifications, and on this hinges much of his interpretation, 



