ASPECTS OF KINETIC EVOLUTION 289 



carefully studied and found to be consistent, and mathematically 

 precise. "Natural laws" are working substitutes for causal 

 explanations. When we understand the ^>/iy, the ' law ' of 

 sequence becomes superfluous. 



There is a frequent impression that the principal object and 

 result of scientific study is generalization, but as a matter of fact 

 the progress of science leads much more often to particulariza- 

 tion, to the recognition of distinctions between things previously 

 supposed to be alike. The powers, forces and principles which 

 formed the subject of abstract discussions in the earlier history 

 of science are being gradually relegated to the background, as 

 our acquaintance with the facts improves and yields insight into 

 the causal connection of events which formerly appeared mere 

 sequences. 



Evolution is not merely a law, but a process. In each species 

 an evolution is going on, in a manner quite analogous to the 

 processes of growth, locomotion and reproduction in the indi- 

 vidual. Certain features of similarity there are, no doubt, in 

 all evolutions, as there are in digestion and other general forms 

 of vital activity. These general similarities can be collected, it 

 may be, and formulated as laws if this method of expression be 

 desired, though this would be, after all, only a special method of 

 describing the processes. Laws themselves have to be ex- 

 plained by resolving them into processes. Only hopelessly 

 metaphysical minds are satisfied with abstract statements, or 

 able to imagine that generalizations are explanations. 



Evolutionists agree that organisms change, but regarding the 

 nature and causes of change great diversity of opinion still 

 exists. The progress thus far is negative. We have learned 

 that evolution is not a merely mechanical process, or due to 

 merely environmental causes, and that it is not a merely cyto- 

 logical process, due to internal mechanisms of descent. It is a 

 superorganic process accomplished through the association of 

 organisms into large specific groups. 



Evolution is, in short, a process of change in organisms, a 

 kind of motion by which plants and animals have advanced 

 from the simple and undifferentiated protoplasm of the lowest 

 types to the highly specialized and complicated structures of the 



