PROGRESS 39 



ability, the occupation of which would be biologically 

 progressive. 



Thus from the well-established biological premisses 

 of (i) the tendency to geometrical increase with 

 consequent struggle for existence, (2) some form of 

 inherited variability, we can deduce as necessary 

 consequence, not only the familiar but none the less 

 fundamental fact of Natural Selection, but also the 

 almost neglected fact that a certain fraction of the 

 guiding force of Natural Selection will inevitably be 

 pushing organisms into changes that are progressive. 



This will of course be true only so far as the general 

 conditions of the environment remain within certain 

 limits : it is probable that too great reductions of 

 temperature or moisture on the surface of the earth 

 would lead to a gradual reversal of progress before the 

 final extinction of life. Up to the present, however, 

 it is clear that such conditions have not occurred, or, 

 possibly, have occurred only for short periods. The 

 general state has been one in which steady, slow pro- 

 gress has been achieved. Progress, like adaptation, is 

 in pre-human evolution almost entirely the resultant 

 of blind chance and blind necessity. 



What corollaries and conclusions may be drawn 

 from the establishment of the fact of biological pro- 

 gress ? In the first place, it permits us to treat human 

 progress as a special case of a more general process. 

 Biologically speaking, the human species is young — 

 not perhaps still in infancy, but certainly not yet 



