It is quite evident, however, that someone had to do the business of the State; and the numerous and very able State papers and memoranda of {141} advice from Olivares to Philip, still in existence,[10] show that every subject of importance was exhaustively explained to the King, naturally from Olivares' point of view, and that, if Philip left the executive power in the hands of the minister, it was not because he was kept in ignorance of the issues involved. Even thus early the main tendency of Olivares' policy was avowed to the King, a policy which was in its essence wise and statesmanlike, but impossible of expeditious consummation. The difficulty which faced Olivares had faced Ferdinand and Isabel and all subsequent Spanish sovereigns, namely, the want of political unity of the country. The "Catholic Kings" had attained a factitious homogeneity by promoting a common spiritual pride, which had given to Spain the temporary force, already well-nigh dead when Olivares took the reins. How could Spain face half Europe in arms, and force orthodoxy on unwilling princes and populations with the resources of ruined Castile alone? Aragonese and Catalans were rich, but held their purse-strings tight. Portugal, with its fine harbours and its rich Oriental trade, held stiffly to the constitution, to respect which Spanish kings had solemnly sworn, and not a ducat of taxes could be imposed upon it by the King of Spain without Portuguese consent, or for other than Portuguese purposes. [Sidenote: Olivares advocates unification]