Frederick is the first writer on the military art who goes to the root of the matter. He always wrote profusely,—most plentifully in bad French verse,—but his “Instructions” are admirable throughout. At the head of the paper stands this motto: “Always move into the field sooner than the enemy;” and this was his course in campaign and battle alike. He asked of the enemy a categorical yes or no to his ultimatum, and upon no struck an instant blow. So novel was Frederick’s quick decisiveness that he was at first looked upon in Europe as a rank disturber of the peace. But his was only the old Roman method revamped.
Underlying this rule was the good of Prussia. This motive he ground into his men’s souls. He demanded as a daily habit extraordinary exertions. His men must perform the unusual at all times. And “from highest officer to last private, no one is to argue, but to obey,” says he. A habit of obedience supplanted fear of punishment. The king’s zeal flowed down through every channel to the ranks. He was himself notoriously the hardest-worked man in Prussia, and his men appreciated the fact.
Next in importance to discipline comes the care of the troops. In his day subsistence tied armies down to predetermined manœuvres. Frederick carried his rations with him, and in his rapid movements made requisitions on the country, as Napoleon, a generation later, did more fully.
Then follows the study of topography. Positions were to Frederick only links in a chain, or resting places, but he ably utilized the lay of the land in his battles. He taught his generals, wherever they might be, to look at the surrounding country and ask themselves, “What should I do if I was suddenly attacked in this position?” He enunciated many maxims scarcely known at his day. “If you divide your forces you will be beaten in detail. If you wish to deliver a battle bring together as many troops as possible.” Frederick did not try to keep everything, but put all his energy into the one important matter. His was no hard and fast system. He did what was most apt. His battle plans were conceived instantly on the ground. What was intricate to others was simple to him and to the Prussian army. Frederick held Hannibal up as a pattern. “Always,” said the king, “lead the enemy to believe you will do the very reverse of what you intend to do.”
Minor operations are clearly treated of. In general the motif of these “Instructions” is attack and initiative. “Prussians,” said he, “are invariably to attack the enemy.” Close with him even if weaker. Make up for weakness by boldness and energy. He opposed passive defence. Every one of his battles was offensive. He complained, indeed, that he had to risk much all his life.
Frederick’s irrepressible courage under misfortune is equalled in history only by Hannibal’s. Fortune was not his servant as she was Alexander’s and Cæsar’s. He thanked himself for his good luck, or rather his successes were due to the fact that he made use of good luck when he had it, and threw no chances away. The magnificence of his warlike deeds is traceable almost solely to his own mental power and remarkable persistency. No danger or difficulty ever, in the remotest degree, changed his purpose or affected his reasoning power. It was this kept the ascendant on his side.
Despite sternest discipline, Frederick was familiar with his men, who knew him as Vater Fritz, and bandied rough jokes with him. “The Austrians are three to one of us, and stoutly entrenched,” said the king, riding the outposts before Leuthen. “And were the devil in front and all around them, we’ll hustle them out, only thou lead us on!” answered a brawny grenadier. “Good-night, Fritz.” He gained such personal love from his men that it seems to have been transmitted as a heritage of the Hohenzollerns. He spurred his men to the most heroic efforts, the most extraordinary feats of daring and endurance. As the complement to this quality, he infused in his enemies a dread of his presence. He utilized the mistakes they made and led them into still others, less from any system than by doing the right thing at the right moment. Strict rules aid only the minds whose conceptions are not clear, and whose execution lacks promptness. Rules were as nothing to Frederick. He observed them, not because they were rules, but because they were grounded on truths which his own mind grasped without them. He broke them when there was distinct gain in so doing. His operations against six armies surrounding him was based on his own maxim, that “Whoso attempts to defend everything runs danger of losing everything,” and he turned from one to the other, risking much to gain much. This idea of Frederick’s was a novel one in his century, whose warfare consisted in an attempt to protect and hold everything by fortresses and partial detachments. In working out this idea he is unapproached.
Frederick never allowed his enemies to carry out their own plans. His movements imposed limitations upon them. He impressed his own personality on every campaign. To carry his victuals with him enabled him to outmanœuvre them, for his enemies relied exclusively on magazines established beforehand. He could select his routes according to the exigencies of the moment, while they must keep within reach of their depots.
Tactically, Frederick stands highest of all soldiers. Strategically he was less great. In strategic movements, his brother, Prince Henry, did occasional work worthy to be placed beside the king’s. Tactically, no one could approach him. His method of handling the three arms was perfect.
Gustavus Adolphus had given new impulse to systematic, intelligent war. But what he did was not understood. His imitators jumbled the old and new systems. They placed too much reliance on fortresses and magazines, and on natural and artificial obstacles; they made strained efforts to threaten the enemy’s communications; they manœuvred for the mere sake of doing something and apart from any general plan; they avoided decisive movements and battles.