Ver. 36. _Some have at first for wits, &c._] The poet having enumerated, in this account of the nature of judgment and its various depravations, the several sorts of bad critics, and ranked them into two general classes, as the first sort,--namely, the men spoiled by false learning--are but few in comparison of the other, and likewise come less within his main view (which is poetical criticism) but keep grovelling at the bottom amongst words and syllables, he thought it enough for his purpose here, just to have mentioned them, proposing to do them right hereafter. But the men spoiled by false taste are innumerable, and these are his proper concern. He therefore, from ver. 35 to 46, subdivides them again into the two classes of the volatile and heavy. He describes, in few words, the quick progression of the one through criticism, from false wit to plain folly, where they end; and the fixed station of the other, between the confines of both; who under the name of witlings, have neither end nor measure. A kind of half-formed creature from the equivocal generation of vivacity and dulness, like those on the banks of Nile, from heat and mud. Ver. 46. _But you who seek, &c._] Our author having thus far, by way of introduction, explained the nature, use, and abuse of criticism, in a figurative description of the qualities and characters of critics, proceeds now to deliver the precepts of the art. The first of which, from ver. 45 to 68, is, that he who sets up for a critic should previously examine his own strength, and see how far he is qualified for the exercise of his profession. He puts him in a way to make this discovery, in that admirable direction given ver. 51. And mark that point where sense and dulness meet. He had shown above, that judgment, without taste or genius, is equally incapable of making a critic or a poet. In whatsoever subject then the critic's taste no longer accompanies his judgment, there he may be assured he is going out of his depth. This our author finely calls, that point where sense and dulness meet. and immediately adds the reason of his precept, the author of nature having so constituted the mental faculties, that one of them can never greatly excel, but at the expense of another. From this state of co-ordination in the mental faculties, and the influence and effects they have upon one another, the poet draws this consequence, that no one genius can excel in more than one art or science. The consequence shows the necessity of the precept, just as the premises, from which the consequence is drawn, show the reasonableness of it.