214 Heredity. 



do not here propose to do spontaneity undoubtedly takes prece- 

 dence of heredity, since it is clear that the derivative presupposes 

 the primitive, and the imitation presupposes the model. 



But if, as now, we take our stand on the ground of science and 

 experiment, heredity becomes the only law; for it alone has a 

 character of constancy, fixedness ; and because it alone is reducible 

 to formulas. Whether we admit with Lamarck the spontaneity of 

 a single type, or with Darwin of three or four types, or of a very 

 great number with Cuvier, so soon as we quit that region of origins 

 and enter the domain of experience we see that nothing subsists 

 except by heredity. 



We have, therefore, to return to our starting-point. Heredity is 

 the law. It is no a priori conception, any more than the axiom, 

 like produces like. It is the accumulated and generalized result 

 of an innumerable mass of experiences. Facts prove that between 

 the partus and the parent there is never anything more than 

 individual differences, and that the immense majority of character- 

 istics is always inherited. Thus, according to the standpoint which 

 we take, it is equally true to say that the law of heredity is always 

 realized, and that it is never realized. The heredity of the greater 

 share of the characteristics is a thing of universal occurrence ; but 

 the heredity of the sum of all the characteristics is never found. 

 So that heredity, while it is the law, is always the exception. But 

 no argument can be drawn from this; for it is a logical necessity 

 that where the conditions of a law are not completely realized the 

 law cannot attain its ideal. 



