Incidents which are past, can be explained clearly, because the reasons therefor are manifest. But men easily deceive themselves concerning the future, which, by a veil of innumerable and impenetrable secondary causes, is concealed from the most prying inspection.
In such situations, how puerile are the projects even of the greatest Strategist. To him, as much as to the tyro, is the future hidden; he knows not what shall happen, even on the next move. How then may he foresee those situations which secondary causes later may produce?
Circumstances most often oblige him to act contrary to his wishes; and in the flux and reflux of fortune, it is the part of prudence to conform to system and to act with consistency. It is impossible to foresee all events.
“It is not possible,” writes the Count de Saxe, “to establish a system without first being acquainted with the principles that must necessarily support it.”
In corroboration of this is the opinion of Frederic the Great:
“Condemned by my unfortunate stars to philosophies on contingencies and on probabilities I employ my whole attention to examine the principle on which my argument must rest and to procure all possible information on that point. Deprived of such precaution, the edifice I erect, wanting a base, would fall like a house of cards.”
Everyone who does not proceed on principle, is inconsistent in his conduct. Equally so, whenever the principle on which one acts is false, i.e., does not apply to the existing situation; all deductions based thereon, if applied to the existing situation, necessarily are false.
“Those principles which the Art of Warfare prescribes, never should be departed from,” writes Frederic the Great, “and generals rigidly should adhere to those circumspections and never swerve from implicit obedience to laws, upon whose exact observance depends the safety of their armies and the success of their projects.”