The greatness of the one will depend on the absolute truth of his idea, considered in the abstract; whereas that of the other will depend on whether or not he correctly judges the given realities and how they may be utilized under the guidance of the truths established by the former. The test of greatness as applied to a political leader is the success of his plans and his enterprises, which means his ability to reach the goal for which he sets out; whereas the final goal set up by the political philosopher can never be reached; for human thought may grasp truths and picture ends which it sees like clear crystal, though such ends can never be completely fulfilled because human nature is weak and imperfect. The more an idea is correct in the abstract, and, therefore, all the more powerful, the smaller is the possibility of putting it into