te,--is it wise or unwise? To be
encouraged or condemned?

It is perhaps the most delicate problem which applied eugenics offers.
It is a peculiarly personal one, and the outsider who advises in such a
case is assuming a heavy responsibility, not only in regard to the
future welfare of the race, but to the individual happiness of X. We can
not accept the sweeping generalization sometimes made that "Strength
should marry weakness and weakness marry strength." No more can we hold
fast to the ideal, which we believe to be utopian, that "Strength should
only marry strength." There are cases where such glittering generalities
are futile; where the race and the individual would both be gainers by a
marriage which produced children that had the family taint, but either
latent or not to a degree serious enough to counteract their value. The
individual must decide for himself with especial reference to the trait
in question and his other compensating qualities; but he should at least
have the benefit of whatever light genetics can offer him, before he
makes his decision.

For the sake of a concrete example, let us suppose that a man, in whose
ancestry tuberculosis has appeared for several generations, is
contemplating marriage. The first thing to be remembered is that if he
marries a woman with a similar family history, their children will have
a double inheritance of the taint, and are almost certain to be affected
unless living in an especially favorable region. It would _in most
cases_ be best that no children result from such a marriage.

On the other hand, the man may marry a woman in whose family consumption
is unknown. The chance of their children being tuberculous will not be
great; nevertheless the taint, the diathesis, will be passed on just the
same, although concealed, possibly to appear at some future time. Such
a marriage is in some ways more dangerous to the race, in the long run,
than that of "weakness with weakness." Yet society at present certainly
has no safe grounds for interference, if such a marriage is made. If the
two persons come of superior stock, it seems _probable_ that the gain
will outweigh the loss. In any event, it is at least to be expected that
both man and woman would have a deliberate consciousness of what they
are doing, and that no person with any honor would enter into a
marriage, concealing a defect in his or her ancestry. Love is usually
blind enough to overlook such a thing, but if it