Read it through once

Some have at first for wits then poets passed Turned critics next and proved plain fools at last Some neither can for wits nor critics pass As heavy mules are neither horse nor ass. Those half-learned witlings, numerous in our isle, As half-formed insects on the banks of Nile Unfinished things one knows not what to call Their generation is so equivocal To tell them would a hundred tongues require, Or one vain wits that might a hundred tire.