In the answer to these two questions lies the whole secret of scientific finance. Colbert was the first finance minister to attempt to give a scientific answer to them, that is, an answer based upon reasoned principle. The reasoned principles adopted by Colbert have been in the main the principles acted upon by most civilised countries from this day to our own. They are principles which underlie the economical system known as Protection, and are the application of the theory of national sovereignty to economical subjects. The seventeenth century, as we have seen, was essentially governed in all political thought by the theory of the solidarity of nations under their kings. All Europe was coalescing into territorial entities under their respective sovereigns. Every such territorial entity guarded itself off from its neighbours by the acquisition of natural frontiers, and by the equipment of a professional army, and emphasised its individuality by its concentration under its king and by the representation of its king and his interests diplomatically at other courts. The idea of a Europe united through the Christian brotherhood of man had passed away. The idea of a Europe united through the cosmopolitan brotherhood of man had not yet come. Between those two theories of brotherhood, men were content to relapse practically into a condition of enmity, and were engaged in building barriers against their neighbours, in developing their own strength as much as possible, and in preventing their neighbours from developing theirs. The same principles governed men’s conduct in economics as in politics. Economic independence was considered just as important for a nation as political independence. To be as strong and resourceful as possible within the territorial limits of the kingdom, to be as independent as possible outside those limits were the recognised objects of every statesman. In the eyes of Colbert it was just as necessary for France that she should not depend upon the foreigner for her bread, as that she should not owe him allegiance for her land. He would have thought it as reckless a piece of criminal folly to derive the food-supply of the nation from certain rivals and possible enemies, as to intrust to them the defence of the frontier. [Sidenote: =Encouragement of home trade and manufactures.=]