the moderns, and the beauties of the ancients. While an author is yet living we estimate his powers by his worst performance, and when he is dead, we rate them by his best.
To works, however, of which the excellence is not absolute and definite, but gradual and comparative ; to works not raised upon prin- ciples demonstrative and scientific, but appeal- ing wholly to observation and experience, no other test can be applied than length of dura- tion and continuance of esteem. What man- kind 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 moun- tain high, without the knowledge of many mountains, and many rivers; so, in the pro- ductions of genius, nothing can be styled ex- cellent till it has been compared with other works of the same kind. Demonstration im- mediately 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