Enthusiasm is the heritage of youth; it plans with audacity and executes with vigor: "It is the leaping lightning," according to Emerson, "not to be measured by the horse-power of the understanding." In the accomplishment of great deeds it is undoubtedly the keenest spur, and consequently those who have become eminent in the history of the world have mostly achieved their greatness before gray hairs have woven themselves about their brows. Unless the tree has borne ample blossoms in the spring, we shall look in vain for a generous crop in the fall. Notwithstanding the abundance of axioms as to youth and rashness dwelling together, we have ample evidence that it is the period of deeds, when the senses are unworn and the whole man is in the vigor of strength and earnestness. Goethe tells us that the destiny of any nation depends upon the opinions of its young men. Let us recall a few examples, in corroboration of this view, among those who have made their mark upon the times in which they lived. Alexander the Great reigned over the Macedonians at sixteen; Scipio was but twenty-nine at the zenith of his military glory; Charles XII.[30] was only nineteen when, as commander-in-chief, he won the famous battle of Narva; Condé was twenty-two when he gained the battle of Rocroi; Scipio the Younger conquered Carthage at thirty-six, and Cortes subdued Mexico at the same age. At thirty Charlemagne was master of France and Germany; at thirty-two Clive had established the British power in India. Hannibal won his greatest victories before he was thirty, and Napoleon was but twenty-seven when he outgeneralled the veteran marshals of Austria on the plains of Italy. George Washington won his first battle as a colonel at twenty-two; Lafayette was a major-general in our army at the age of twenty. Nor are we to look only for youthful greatness among those who have won laurels in war. William Pitt was prime minister of England at twenty-four; Calhoun had achieved national greatness before he was thirty; while the names of John Adams, Alexander Hamilton, and the elder Pitt in England also suggest themselves in this connection.[31]