mmarise: you know there is
wine in the soup. You do not know how many wines there are in the
soup, because you do not know how many wines there are in the world.
And you never will know, because all chemists, all cooks, and all
common-sense people tell you that the soup is of such a sort that it
can never be chemically analysed. That is a perfectly fair parallel to
the hereditary element in the human soul. There are many ways in which
one can feel that there is wine in the soup, as in suddenly tasting a
wine specially favoured; that corresponds to seeing suddenly flash on
a young face the image of some ancestor you have known. But even then
the taster cannot be certain he is not tasting one familiar wine among
many unfamiliar ones--or seeing one known ancestor among a million
unknown ancestors. Another way is to get drunk on the soup, which
corresponds to the case of those who say they are driven to sin and
death by hereditary doom. But even then the drunkard cannot be certain
it was the soup, any more than the traditional drunkard who is certain
it was the salmon.

Those are the facts about heredity which anyone can see. The upshot of
them is not only that a miss is as good as a mile, but a miss is as
good as a win. If the child has his parents' nose (or noses) that may
be heredity. But if he has not, that may be heredity too. And as we
need not take heredity lightly because two generations differ--so we
need not take heredity a scrap more seriously because two generations
are similar. The thing is there, in what cases we know not, in what
proportion we know not, and we cannot know.

Now it is just here that the decent difference of function between Dr.
Saleeby's trade and mine comes in. It is his business to study human
health and sickness as a whole, in a spirit of more or less
enlightened guesswork; and it is perfectly natural that he should
allow for heredity here, there, and everywhere, as a man climbing a
mountain or sailing a boat will allow for weather without even
explaining it to himself. An utterly different attitude is incumbent
on any conscientious man writing about what laws should be enforced or
about how commonwealths should be governed. And when we consider how
plain a fact is murder, and yet how hesitant and even hazy we all grow
about the guilt of a murderer, when we consider how simple an act is
stealing, and yet how hard it is to convict and punish those rich
commercial pirates who steal the most