THE SPECIFIC CHARACTERISTICS OF VITALITY 555 



arise until the related neuroplasm has attained to a certain 

 degree of functional differentiation. 



Certain biologists, for instance Haeckel, have, on the con- 

 trary, assumed that consciousness does exist in every animal 

 form from amoeba to man ; but as this position is absolutely 

 beyond the reach of proof, it cannot be used as a datum for 

 further argument. 



The assumption seems extremely improbable ; were it true, 

 the fcetus in utero, for instance, would be a self-conscious 

 existence ; but if we are sure of anything, we are sure that is 

 not. If we could be certain that consciousness is an accom- 

 paniment of all living matter, then we could regard it as an 

 additional differentia of protoplasm, for no one holds, save as 

 poetry, that non-living matter is conscious. 



In those animals which possess it, consciousness is a 

 characteristic of life sui generis, in which respect it resembles 

 the power of producing anti-bodies ; but only somewhat 

 highly differentiated protoplasm possesses either of these 

 properties. 



Enough has been said to justify us in refusing to see no 

 essential differences between matter in the living and in the 

 non-living state. That living matter had its origin in the 

 non-living is a conceivable evolutionary possibility ; but that 

 we may discover in matter which has never lived all the pro- 

 perties whereby we recognise vitality does not seem a correct 

 interpretation of the world of life as we find it. 



By magnifying resemblances and by explanations based on 

 analogies, we can endow the non-living with the semblance of 

 life, but we are somehow certain after all that differences are 

 there, and that it is poetry and not science that has been 

 enriched. Between the living and the non-living there is a 

 great gulf fixed, and no efforts of ours, however heroic, have 

 as yet bridged it over. 



