and the silly and imbecile do
not take a part in the gatherings." On this last point, by the way, I am
not convinced. The research on the heredity of mental and moral
characters leads naturally to eugenics, as in the 'Macmillan' paper of
1865. But before dealing with this I must say a few words about what, in
the opinion of some, is Galton's chief claim to eminence--the study of
heredity as a whole. There is no doubt that he was the first to treat
thoroughly and in a strict statistical method, the steps by which one
generation passes into the next. He was pre-eminently a lover of
statistics, he was indeed what Goschen called himself, "a passionate
statistician."

He used Gauss's Law of Error, which Quetelet had already applied to human
measurements. "The primary objects," he says, "of the Gaussian Law of
Error were exactly opposed, in one sense to those to which I applied
them. They were to get rid of, or to provide, a just allowance for
errors. But these errors or deviations were the very things I wanted to
preserve and to know about."

This conception of variation impressed him deeply, so that he remembered
the exact spot in the grounds of Naworth Castle where it first occurred
to him "that the laws of heredity {28} were solely concerned with
deviations expressed in statistical units."

What may be called the final result of Galton's work in heredity is, I
imagine, his _ancestral law_, namely that "the average contribution of
each parent" to its offspring is one quarter, or in other words, that
half of the qualities of the child can be accounted for when we know its
father and mother. In the same way the four grandparents together
contribute one quarter, and so on. He illustrates this by calculating
how much Norman blood a man has who descends from a Baron of William the
Conqueror's. Assuming that the Baron weighed 14 stone, his descendant's
share in him is represented by 1/50 grain. {29}

This side of Galton's work is, in the judgment of many, his greatest
claim to distinction as a master in the science of heredity. How far
this is so I shall not attempt to pronounce. It is possibly still too
soon to do so. Nevertheless, it seems to me that Mendelism, the main
facts of which are no longer in dispute, will compel the world (if it has
not already done so) to look at variation in a very different way to that
of Galton. The Mendelian does not, and never will, look at variation
merely as a "deviation ex