132 On the Inheritance of the Mental and Moral Characters in Man 
terms, we expect correlation between home influence and moral qualities, and 
between education and mental power, and the bulk of men too rashly, perhaps, 
conclude that the home and the school are the chief sources of those qualities 
on which social stability so largely depends. We are too apt to overlook the 
possibility that the home standard is itself a product of parental stock, and 
that the relative gain from education depends to a surprising degree on the 
raw material presented to the educator. We are agreed that good homes and 
good schools are essential to national prosperity. But does not the good home 
depend upon the percentage of innately wise parents, and the good school depend 
quite as much on the children's capacity, as on its staff and equipment ? 
It is quite possible to accept these views and yet believe that the moral 
and mental characters are inherited in either a quantitatively or a qualitatively 
different manner from the physical characters. Both may be influenced by 
environment, but the one in a far more marked way than the other. Since 
the publication of Francis Galton's epoch-making books, Hereditary Genius and 
English Men of Science, it is impossible to deny in toto the inheritance of 
mental characters. But we require to go a stage further and ask for an exact 
quantitative measure of the inheritance of such characters and a comparison of 
such measure with its value for the physical characters. 
Accordingly some six or seven years ago I set myself the following problem : 
What is the quantitative measure of the inheritance of the moral and mental 
characters in man, and how is it related to the corresponding measure of the 
inheritance of the physical characters ? 
The problem really resolved itself into three separate investigations : — 
(a) A sufficiently wide inquiry into the actual values of inheritance of the 
physical characters in man. 
This investigation was carried out by the measurement of upwards 
of 1000 families. We thus obtained ample means of deterjnining 
both for parental and fraternal relationships the quantitative measure 
of resemblance. 
{b) A comparison of the inheritance of the physical characters in man with 
that of the physical characters in other forms of life. 
This has been made for a considerable number of characters in 
diverse species, with the general result that there appears to be 
no substantial difference, as far as we have been able to discover, 
between the inheritance of physique in man, and its inheritance in 
other forms of life. 
(c) An inquiry into the inheritance of the moral and mental characters 
in man. 
This is the part of my work with which we are at present chiefly 
concerned, and I want to indicate the general lines along which my 
argument runs. 
