280 Heredity. 



life, which, in proportion as we ascend the scale of being, passes 

 from the simultaneous to the successive form which is the neces- 

 sary condition of consciousness and tends more and more to- 

 ward perfect unity, personality, the ego, without ever attaining it 

 absolutely. 



Thus the parallelism is complete between these two orders of 

 facts, which at bottom are only one ; and so we can understand, 

 or at least suspect, how the two orders of heredity may flow from 

 the same cause. 1 Enough, however, has been said hypothetically, 

 and we must conclude. 



To sum up : we think we have proved that psychological 

 heredity has its cause in physiological heredity, and that this 

 cannot be reasonably disputed. The two heredities, being thus 

 reduced to one, we again sought for the cause of heredity, and 

 found only a hypothesis, probable indeed, but which, lying beyond 

 the limits of experience, cannot be verified. The definite result of 

 these researches and the point is so important that it must be 

 again and again repeated is that heredity is identity as far as is 

 possible ; it is one being in many. ' The cause of heredity,' says 

 Hackel, ' is the partial identity of the materials which constitute 

 the organism of the parent and child, and the division of this 

 substance at the time of reproduction.' Heredity, in fact, is to be 

 considered only as a kind of growth, like the spontaneous division 

 of a unicellular plant of the simplest organization. 



Having studied the Facts, the Laws, and the Causes, we have 

 now to look at the practical side of heredity, the Consequences. 



1 Compare the very bold and ingenious hypothesis of Herbert Spencer {Psy- 

 chology, 2nd Edition, 139), of which the following is the substance. Our 

 sciences, our arts, our civilization, all social phenomena, however multitudinous 

 and complicated, are reduced on final analysis to a certain number of feelings 

 and thoughts. These in turn are referred to the primitive sensations, to the 

 data of the five senses. The senses are reducible to touch. Physiology goes 

 far to confirm the saying of Democritus, that all the senses are modifications of 

 touch. Touch itself has its basis in those primordial properties which distin- 

 guish organic from inorganic matter. And many facts point to the conclusion 

 that sensibility of all kinds takes its rise out of those fundamental processes 

 of integration and disintegration, in which life in its primitive form consists. 



