To take but one instance. How confident were the assertions made in the days preceding the unification of the states of the North American continent regarding the insuperable barriers that stood in the way of their ultimate federation! Was it not widely and emphatically declared that the conflicting interests, the mutual distrust, the differences of government and habit that divided the states were such as no force, whether spiritual or temporal, could ever hope to harmonize or control? And yet how different were the conditions prevailing a hundred and fifty years ago from those that characterize present-day society! It would indeed be no exaggeration to say that the absence of those facilities which modern scientific progress has placed at the service of humanity in our time made of the problem of welding the American states into a single federation, similar though they were in certain traditions, a task infinitely more complex than that which confronts a divided humanity in its efforts to achieve the unification of all mankind.

Who knows that for so exalted a conception to take shape a suffering more intense than any it has yet experienced will have to be inflicted upon humanity? Could anything less than the fire of a civil war with all its violence and vicissitudes--a war that nearly rent the great American Republic--have welded the states, not only into a Union of independent units, but into a Nation, in spite of all the ethnic differences that characterized its component parts? That so fundamental a revolution, involving such far-reaching changes in the structure of society, can be achieved through the ordinary processes of diplomacy and education seems highly improbable. We have but to turn our gaze to humanity's blood-stained history to realize that nothing short of intense mental as well as physical agony has been able to precipitate those epoch-making changes that constitute the greatest landmarks in the history of human civilization.