104: REPLIES TO CRITICISMS. 



The same primary factors have been co-operating with 

 those secondary factors, metcorologic and geologic, pre 

 viously derived from them. Nowhere do we find a break 

 in the ever-complicating series ; for there is a manifest 

 connexion between those movements which various complex 

 compounds undergo during their isomeric transformations, 

 and those changes of form undergone by the protoplasm 

 which we distinguish as living. Strongly contrasted as they 

 eventually become, biological phenomena are at their root 

 inseparable from geological phenomena inseparable from 

 the aggregate of transformations continually wrought in the 

 matters forming the Earth s surface by the physical forces 

 to which they are exposed. Further stages I need not par 

 ticularize. The gradual development out of the biological 

 group of phenomena, of the more specialized group we 

 class as psychological, needs no illustration. And when we 

 come to the highest psychological phenomena, it is clear 

 that since aggregations of human beings may be traced 

 upwards from single wandering families to tribes and nations 

 of all sizes and complexities, we pass insensibly from the 

 phenomena of individual human action to those of corporate 

 human action. To resume, then, is it not manifest that in 

 the group of sciences Astronomy, Geology, Biology, Psy 

 chology, Sociology, we have a natural group that admits 

 neither of disruption nor change of order? Here there is 

 both a genetic dependence, and a dependence of interpre 

 tations. The phenomena have arisen in this succession in 

 cosmical time ; and complete scientific interpretation of each 

 group depends on scientific interpretation of the preceding 

 groups. No other science can be thrust in anywhere with 

 out destroying the continuity. To insert Physics between 

 Astronomy and Geology, would be to make a break in the 

 history of a continuous series of changes ; and a like break 

 would be produced by inserting Chemistry between Geology 

 and Biology. It is true that Physics and Chemistry arc 



