the age of discovery broadened their horizons from the world of the Mediterranean to the whole wide world. To bring this description of the elaboration and development of social, economic and political ideas right down to the discussions of the present day, would be to introduce issues altogether too controversial for the scope and intentions of this book. But regarding these things, as we do here, from the vast perspectives of the student of world history, we are bound to recognize that this reconstruction of these directive ideas in the human mind is still an unfinished task—we cannot even estimate yet how unfinished the task may be. Certain common beliefs do seem to be emerging, and their influence is very perceptible upon the political events and public acts of to-day; but at present they are not clear enough nor convincing enough to compel men definitely and systematically towards their realization. Men’s acts waver between tradition and the new, and on the whole they rather gravitate towards the traditional. Yet, compared with the thought of even a brief lifetime ago, there does seem to be an outline shaping itself of a new order in human affairs. It is a sketchy outline, vanishing into vagueness at this point and that, and fluctuating in detail and formulæ, yet it grows steadfastly clearer, and its main lines change less and less. CONSTRUCTIONAL DETAIL OF THE FORTH BRIDGE CONSTRUCTIONAL DETAIL OF THE FORTH BRIDGE _Photo: Baker & Hurtzig_ It is becoming plainer and plainer each year that in many respects and in an increasing range of affairs, mankind is becoming one community, and that it is more and more necessary that in such matters there should be a common world-wide control. For example, it is steadily truer that the whole planet is now one economic community, that the proper exploitation of its natural resources demands one comprehensive direction, and that the greater power and range that discovery has given human effort makes the present fragmentary and contentious administration of such affairs more and more wasteful and dangerous. Financial and monetary expedients also become world-wide interests to be dealt with successfully only on world-wide lines. Infectious diseases and the increase and migrations of population are also now plainly seen to be world-wide concerns. The greater power and range of human activities has also made war disproportionately destructive and disorganizing, and, even as a clumsy way of settling issues between government and government and people and people, ineffective. All these things clamour for controls and authorities of a greater range and greater comprehensiveness than any government that has hitherto existed.