Do not repeat the tactics which have gained you one victory, but let
your methods be regulated by the infinite variety of circumstances.
As Wang Hsi sagely remarks: “There is but one root-principle (理)
underlying victory, but the tactics (形) which lead up to it are
infinite in number.” With this compare Col. Henderson; “The rules
of strategy are few and simple. They may be learned in a week.
They may be taught by familiar illustrations or a dozen diagrams.
But such knowledge will no more teach a man to lead an army like
Napoleon than a knowledge of grammar will teach him to write like
Gibbon.”