This theory was developed by the Russian Jewish scholar (Isaiah Berlin), and it is known as the hedgehog and fox theory, which he took its essence from a verse by one of the ancient Greek poets, in which he explained that the hedgehog knows one way to war and revenge, while the fox uses many ways and methods to achieve his goal. Therefore, we see that Sultan Saladin did not follow the path of the hedgehog in achieving his goals, but rather he applied the fox theory and resorted to using various methods to liberate Jerusalem, which he succeeded in doing in the year (583 AH/1187 AD).