But the painstaking gentry, when heaven sends them genius enough, are the most instructive sort, and they are those to whom we shall appeal while time and truth can meet together.  A well-read writer, with good taste, is one who has the command of the wit of other men;[280] he searches where knowledge is to be found; and though he may not himself excel in invention, his ingenuity may compose one of those agreeable books, the deliciae of literature, that will outlast the fading meteors of his day.  Epicurus is said to have borrowed from no writer in his three hundred inspired volumes, while Plutarch, Seneca, and the elder Pliny made such free use of their libraries; and it has happened that Epicurus, with his unsubstantial nothingness, has “melted into thin air,” while the solid treasures have buoyed themselves up amidst the wrecks of nations.

On this subject of quotation, literary politics,—­for the commonwealth has its policy and its cabinet-secrets,—­are more concerned than the reader suspects.  Authorities in matters of fact are often called for; in matters of opinion, indeed, which perhaps are of more importance, no one requires any authority.  But too open and generous a revelation of the chapter and the page of the original quoted has often proved detrimental to the legitimate honours of the quoter.  They are unfairly appropriated by the next comer; the quoter is never quoted, but the authority he has afforded is produced by his successor with the air of an original research.  I have seen MSS. thus confidently referred to, which could never have met the eye of the writer.  A learned historian declared to me of a contemporary, that the latter had appropriated his researches; he might, indeed, and he had a right to refer to the same originals; but if his predecessor had opened the sources for him, gratitude is not a silent virtue.  Gilbert Stuart thus lived on Robertson:  and as Professor Dugald Stewart observes, “his curiosity has seldom led him into any path where the genius and industry of his predecessor had not previously cleared the way.”  It is for this reason some authors, who do not care to trust to the equity and gratitude of their successors, will not furnish the means of supplanting themselves; for, by not yielding up their authorities, they themselves become one.  Some authors, who are pleased at seeing their names occur in the margins of other books than their own, have practised this political management; such as Alexander ab Alexandro, and other compilers of that stamp, to whose labours of small value we are often obliged to refer, from the circumstance that they themselves have not pointed out their authorities.