To works, however, of which the excellence is not absolute and definite, but gradual and comparative; to works not raised upon principles demonstrative and scientifick, but appealing wholly to observation and experience, no other test can he applied than length of duration and continuance of esteem.  What mankind have long possessed they have often examined and compared; and if they persist to value the possession, it is because frequent comparisons have confirmed opinion in its favour.  As among the works of nature no man can properly call a river deep, or a mountain high, without the knowledge of many mountains, and many rivers; so in the productions of genius, nothing can be stiled excellent till it has been compared with other works of the same kind.  Demonstration immediately displays its power, and has nothing to hope or fear from the flux of years; but works tentative and experimental must be estimated by their proportion to the general and collective ability of man, as it is discovered in a long succession of endeavours.  Of the first building that was raised, it might be with certainty determined that it was round or square; but whether it was spacious or lofty must have been referred to time.  The Pythagorean scale of numbers was at once discovered to be perfect; but the poems of Homer we yet know not to transcend the common limits of human intelligence, but by remarking, that nation after nation, and century after century, has been able to do little more than transpose his incidents, new-name his characters, and paraphrase his sentiments.

The reverence due to writings that have long subsisted arises therefore not from any credulous confidence in the superior wisdom of past ages, or gloomy persuasion of the degeneracy of mankind, but is the consequence of acknowledged and indubitable positions, that what has been longest known has been most considered, and what is most considered is best understood.

The Poet, of whose works I have undertaken the revision, may now begin to assume the dignity of an ancient, and claim the privilege of established fame and prescriptive veneration.  He has long outlived his century, the term commonly fixed as the test of literary merit.  Whatever advantages he might once derive from personal allusions, local customs, or temporary opinions, have for many years been lost; and every topick of merriment, or motive of sorrow, which the modes of artificial life afforded him, now only obscure the scenes which they once illuminated.  The effects of favour and competition are at an end; the tradition of his friendships and his enemies has perished; his works support no opinion with arguments, nor supply any faction with invectives; they can neither indulge vanity nor gratify malignity; but are read without any other reason than the desire of pleasure, and are therefore praised only as pleasure is obtained; yet, thus unassisted by interest or passion, they have past through variations of taste and changes of manners, and, as they devolved from one generation to another, have received new honours at every transmission.