HEREDITY IN PHYSIOLOGY, IN MEDICINE, ETC. 345 
tive races, it is true, and they still are the law of savage 
tribes; but nothing, to begin with, proves that heredity is 
the cause of this. Such a reappearance, during a longer 
or shorter tract of time, of societies exactly alike, seems to 
be much more properly attributable to the potent and irre- 
sistible instinct of imitation, and to positive respect for 
rites and customs commanded by religion. With these 
tribes, the future is like the present, and the present re- 
peats the past only because the same unbending rule, the 
same authority and the same tyrannical superstition, press 
on all alike. Nothing has any strength or respect among 
such people, except through tradition, and tradition among 
them is merely the honored memory of a will once of old 
expressed by mysterious powers. When the English de- 
sire to interest the Hindoos in the works of communication 
and of hygiene that they are effecting in India, they are 
even at this day forced to convince them first that the useful- 
ness of such works was well understood by the Brahmans 
in the remotest times, so difficult is it for that ancient race 
to believe that a rule can be obligatory unless it is tradi- 
tional, 
At all events, and whatever part heredity may be al- 
lowed in this matter, it is certain that its part is not great, 
because that strange homogeneity of primitive races, in- 
stead of maintaining and strengthening itself, yields sooner 
or later to diversity. Every people in turn is invaded by 
a force as powerful for action counter to that of hereditary 
influences as it is in striking off the iron yoke of primal 
customs. It wasin Greece, nearly three thousand years ago, 
that the first throe of that force shaped and worked what 
Goethe calls “the liberation of humanity.” Since then, 
the crossings of distinct races, new needs and the diversi- 
fied inventions which they have suggested without end, the 
ideas awakened in man by the ever-growing closeness of 
his contact with Nature, have brought into the place of 
