92 THE SHADOW OF THE WORLD'S FUTURE
realise that in the nature of the case effective occupation
 is the only safeguard ultimately of their rights.
Dense and expanding populations will be compelled,
whether they will or no, to challenge cases of ineffective
occupation, and that will be one of the great problems
of the very near future. It is a problem that certainly
deeply concerns peoples whose countries exhibit very
small population-density, more especially when they
are countries capable of carrying much greater numbers.
A refusal to face a question of this kind is not only
fatuous; it is also morally reprehensible in the last
degree. And it is not too much to say that such
refusal may be the presage of doom.
We do well, of course, to bear in mind that people
of our own race and nationality not only have a first
claim to consideration because their language is the
same, and their ideals, traditions, social habits are
akin, but also for the reason that those who wish to
emigrate from their own lands, if adults, are often
not the most eminently desirable. This, however,
hardly applies to the younger folk, and for this reason
they constitute usually the most desirable among
those who wish to migrate. Hence the importance
of such a migration as has been called the “little
brother ” movement. We are not, however, here
dealing with the grounds for preferences for particular
 classes of migrants. We revert to the general
Juestion.
What has been said above reminds us that behind
any serious study of the population problem lies a
question of ethics. It is this: — When sensible differences
 exist between the actual and the possible populations
 of given countries, what principle is to guide
world-politics in regard to the situation thus existing? »’
There are, it would appear, at least four fundamental
elements in this question, and they call for solutions.
These elements are as follow, viz. :—