History knows men who did not begin till they were in the middle of their days. It is only on approaching or entering the forties that some people seem to strike the line of their real achievement. Up to that period they may have been active and useful, but they have not awakened to their vocation; as yet they are unconscious of their true powers. While this does not apply to the spheres of art and music, it is far from being uncommon in politics and literature. There, as any student of biography soon becomes aware, a man may not find himself till he is about forty. Sometimes it is then or thereabouts—nel mezzo del cammin di nostra vita—that something happens, and a man of action, a thinker, an author, first gets the chance or the idea of doing what turns out to be the most significant thing in his career.