From this great difficulty, biography is entirely free, and thence the superior interest with which, when properly treated, works of that description are attended. We are so constituted that we must concentrate our interest; dispersion is fatal to its existence. Every novelist and romance-writer knows this; there must always be a hero and a heroine; but two or three heroes and heroines would prove fatal to the interest. Ariosto tried to divide the interest of the reader among the adventures of a dozen knights-errant; but even his genius proved unequal to the task, and he was obliged to concentrate the whole around the fabulous siege of Paris to restore the broken unity of his power. The great and signal advantage of biography is, that, from its very nature, it possesses that personal interest and individual character which the epic poet and novelist feel to be essential to the moving of the human heart, but which the historian so often finds himself unable to attain, without omitting some important parts of his subject, or giving undue prominence to the characters of individual men. For this reason it is, that the most popular works which ever have been written have been biographies of illustrious men. No one would think of comparing the intellect of Plutarch to that of Tacitus, his eloquence to that of Cicero's, yet he has made perhaps a greater impression on the imagination of subsequent ages than either of these illustrious men. If we examine the images of the mighty of former days which are engraven on our minds, we shall find that it is not so much the pictured pages of Livy or Quintus Curtius, as the "Lives of Plutarch," which have given them immortality. We complain of his gossip, we lament his superstition, we smile at his credulity, but we devour his pages; and, after the lapse of seventeen hundred years, they remain one of the most generally popular works in existence. It is the same in modern times. No one would think of comparing Boswell, in point of intellect, to Johnson; in point of eloquence to Burke; in point of genius to Gibbon; yet he has produced a work superior in general interest to any of these illustrious men, and which is daily read by thousands, to whom the "Reflections on the French Revolution," the moral essays of the "Rambler," and the "History of the Decline and Fall," will for ever remain unknown.