Physiological and Psychological Heredity. 269 



it is no longer acceptable ; and it would not be rash to assert that 

 the great minds who in that age professed this dualism would now 

 be the first to reject it. We have seen that in our time there is a 

 growing tendency to admit an intimate correlation, a mutual inter- 

 change between the two orders of phenomena, so that the 

 difficulty is not to unite but to separate them ; and we could not 

 explain why this radical dualism is still so accredited, did we not 

 know that it is yet more difficult to extirpate an old error than to 

 bring a new truth into acceptance. 



Without insisting on this hypothesis, which in itself alone in- 

 cludes all the difficulties of both the others, let us proceed to 

 examine them. 



i. It might be held that psychological heredity is the cause of 

 physiological heredity. This proposition is evidently the one that 

 is maintained by the idealists and the animists. We are not aware 

 that they have laid it down in precise and explicit form, and this 

 no doubt because they have been very little concerned with the 

 problem of heredity, which is chiefly physiological. And, indeed, 

 it is worthy of remark that while spiritualistic philosophy has been 

 much occupied with the future destiny of the soul, it has bestowed 

 very little thought on its origin. It has always inquired whither 

 we are going, and but seldom whence we come. And yet these 

 two problems are intimately connected, and are both equally 

 mysterious. 



Theologians have taken more pains to work out this question. 

 It is one that is closely connected with the foundation whereon 

 Christianity rests, the transmission of original sin. Their opinions 

 are not very harmonious, but are of no importance here. They 

 may be reduced under two heads. 



Some have taught that God, the only and the immediate origin 

 of souls, creates, at the instant of conception, a special soul for 

 the body which comes into being. 



Others hold that all souls are sprung, like all bodies, from the 

 first man, and that they are propagated in the same way that is, by 

 generation. This would seem to be the opinion of the majority. 

 Tertullian, St. Jerome, and Luther held it, as also two philosophers, 

 Malebranche and Leibnitz. The latter held it to be ' the only 

 doctrine, wherein philosophy can harmonize with religion.' 



