Frederick’s history of his times is, like Caesar’s Commentaries, one of the most important documents of historical literature.  True, like the Roman general, like all practical statesmen, he stated facts as they are reflected in the soul of a participant.  He does not give due value to everything or full justice to everybody, but he knows infinitely more than is revealed to one at a distance, and he wrote of some of the motives underlying the great events, not without prejudice, yet with magnanimity toward his opponents.  Writing at times without the enormous reference material which a professional historian must collect about him, he was occasionally deceived by his memory and his judgment, though both were very reliable.  He was, moreover, composing an apology for his house, his politics, his campaigns; and, like Caesar, he sometimes ignores facts or interprets them as he wishes them to go down to posterity; but his love of truth and the frankness with which he treats his house and his own actions are no less admirable than his sovereign calm and the ease with which he soars above events, in spite of the little rhetorical embellishments which were due to the taste of his time.

His many-sidedness is as astonishing as his productiveness.  One of the greatest military writers, a historian of importance, a clever poet, and at the same time a popular philosopher, a practical statesman, even a writer of very free and easy anonymous pamphlets, and sometimes a journalist, he was always ready to take up his pen for anything that inspired him and aroused his passions or enthusiasm, or to attack, in verse or prose, any one who provoked or annoyed him—­not only the pope and the Empress, the Jesuits and the Dutch journalists, but also old friends if they seemed lukewarm to him,—­which he could not endure,—­or if they actually threatened to break with him.  Never since Luther has there been such a belligerent, relentless, untiring writer.  As soon as he put pen to paper he was like Proteus, everything:  sage or intriguer, historian or poet, whatever the situation demanded, always an active, fiery, intellectual—­sometimes also an ill-mannered—­man, with never a moment’s thought of his royal position.  Whatever he liked he praised in poems or eulogies:  the noble doctrines of his own philosophy, his friends, his army, religious liberty, independent investigation, tolerance, and popular education.

The conquering power of Frederick’s mind had reached out in all directions.  When ambition inspired him to victory it seemed as if there were no obstacle that would check him.  Then came the years of trial—­seven years of terrible, heartrending cares—­the great period, in which the heaviest tasks that ever a man accomplished were laid upon his rich, ambitious spirit, in which almost everything perished which was his own possession, joy and happiness, peace and selfish comfort; in which also many pleasing and graceful characteristics of