classes cannot be suffered to continue.  It is also plain to all who have examined the subject that the campaign against certain diseases, the malignity and wide diffusion of which are being more fully realised every year, cannot be successful through medical methods alone.  If the institution in question were abolished, medical science would soon reduce these scourges to manageable limits, and might at last exterminate them altogether; but while it continues there is no hope of doing this.  I believe then that the time will come when the trade in vice will cease; and if I am right, early marriages will become the rule in all classes.  This will render the population question more acute, especially as the diseases which we hope to extirpate are the commonest cause both of sterility and of infant mortality.  Under this pressure, we must expect to see preventive methods widely accepted as the least of unavoidable evils.

When we reflect on the whole problem in its widest aspects, we see that civilised humanity is confronted by a Choice of Hercules.  On the one side, biological law seems to urge us forward to the struggle for existence and expansion.  The nation in that case will have to be organised on the lines of greatest efficiency.  A strong centralised government will occupy itself largely in preventing waste.  All the resources of the nation must be used to the uttermost.  Parks must be cut up into allotments; the unproductive labours of the scholar and thinker must be jealously controlled and limited.  Inefficient citizens must be weeded out; wages must be low and hours of work long.  Moreover, the State must be organised for war; for its neighbours, we must suppose, are following the same policy.  Then the fierce extra-group competition must come to its logical arbitrament in a life and death struggle.  And war between two over-peopled countries, for both of which more elbow-room is a vital necessity, must be a war of complete expropriation or extermination.  It must be so, for no other kind of war can achieve its object.  The horrors of the present conflict will be as nothing compared with a struggle between two highly-organised State socialisms, each of which knows that it must either colonise the territory of the other or starve.  It is idle to pretend that such a necessity will never arise.  Another century of increase in Europe like that of the nineteenth century would bring it very near.  If this policy is adopted, we shall see all the principal States organising themselves with a perfection far greater than that of Germany to-day, but taking German methods as their model; and the end will be the extermination of the smaller or looser organisations.  Such a prospect may well fill us with horror; and it is terrible to find some of the ablest thinkers of Germany, such as Ernst Troeltsch, writing calm elegies over ‘the death of Liberalism’ and predicting the advent of an era of cut-throat international competition.  Juvenal speaks of the folly of propter vitam vivendi perdere causas; and who would care to live in such a world?  But does Nature care whether we enjoy our lives or not?