“Besides the great utility which general history derives from private authorities, other advantages no less important,” says this learned and ingenious biographer, “may be obtained from them. It is from observing individuals, that we may be enabled to draw the outlines of that extraordinary, complicated being, man. The characteristics of any country or age must be deduced from the separate characters of persons, who, however distinguishable in many respects, still preserve a family-likeness. From the life of almost any one individual, but chiefly from the lives of such eminent men as seemed destined to enlighten or to adorn society, instructions may be drawn, suitable to every capacity, rank, age or station. Young men, aspiring to honours, cannot be too assiduous in tracing the means by which they were obtained: by observing with what difficulty they were preserved, they will be apprized of their real value, estimate the risks of the purchase, and discover frequent disappointment in the possession.” “It is from the number and variety of private memoirs, and the collision of opposite testimonies, that the judicious reader is enabled to strike out light, and find his way through that darkness and confusion in which he is at first involved.” “Who does not wish that Cæsar had lived to finish his Commentaries; and that Pompey’s sons, instead of fighting their father’s cause, had employed themselves in writing his life?—What a valuable legacy would Cicero have left us, if, instead of his philosophical works, he had written the memoirs of his own times! Or how much would Tyro, to whom posterity is so much indebted for the preservation of his master’s letters, have encreased that obligation, if, from his own knowledge, he had connected and explained them! The life of Agricola, by his son-in-law Tacitus, is undoubtedly one of the most precious monuments of antiquity.” ----- The writer of the present work has therefore ventured, with all due deference to the public opinion, to pursue the course here described. And in doing this, he presumes that the comprehensive range he has allowed himself has enabled him to render his memoirs, even of a “philosopher,” not altogether barren of incidents, nor destitute, he trusts, either of pleasing information or useful instruction. ======================================== NOTE.—The reader is requested to substitute (with his _pen_) the word _Earth_, in the place of “_Sun_,” in the sixth line of the note numbered (18), page xxxii. of the foregoing Introduction: the error in the print is an essential one; and passed unobserved, until it was too late to correct it in the press. At the same time the reader will be pleased to insert the word _security_, in the place of “_scarcity_,” in the ninth line from the top of page xlii.