4 i 4 SCIENCE PROGRESS 



It has, however, been very widely felt that complete con- 

 tinuity never could be established, on account of the factor 

 called mind. It may be admitted that there is complete 

 material continuity in evolution from the most primitive forms 

 of inorganic matter to the most advanced forms of organic 

 matter ; and from the properties of the most elementary sub- 

 stances to the manifestations of the highest forms of life (for 

 under this view the manifestations of life are considered as 

 simply the physical and chemical properties of the highly 

 complex substances composing living matter). It is alleged 

 on the other hand that this continuity is only a material 

 continuity : that living bodies manifest a mental or spiritual 

 life, of which no counterpart exists in inorganic bodies : that 

 this new spiritual factor appears for the first time somewhere 

 in the evolutional chain, and that at the point of its appearance 

 there must be a true discontinuity, which abruptly and funda- 

 mentally severs those bodies which have it from those which 

 do not have it. Opinion has differed widely as to the precise 

 point at which this supposed transition has occurred. Descartes 

 placed it between men and other animals. He regarded all 

 animals except man as soulless machines, devoid of sensation 

 or any kind of feeling. Lamarck placed it between his classes 

 of worms and insects, where he imagined the earliest traces of 

 a nervous system appeared. Modern philosophers are inclined 

 to place it at a still earlier stage, and in fact to mark it as the 

 dividing line between organic and inorganic. 



The whole problem is nevertheless a survival of mediaeval 

 modes of thought, possessing no greater reality than the cognate 

 problem as to the site of the soul. It rests upon a totally false 

 conception of the relation between mind and matter. It is based 

 upon the assumption that the universe exhibits two agencies, by 

 which all events are brought to pass. The one agency is that 

 dealt with in our mechanics, physics, and chemistry : it works 

 by an absolutely uniform and invariable procedure, which has 

 been to some extent analysed, crystallised, and formulated as 

 the laws of science. The other supposed agency is the spiritual : 

 it works in a wholly capricious and arbitrary manner, displays 

 no kind of uniformity, and is by its very nature incapable ot 

 reduction to any scientific laws. 



At the outset of civilisation, nearly all events appeared to 

 be of this fickle and disconnected character. Few uniformities 



