I should say that the reason why even learned men differ so widely and display so great a range of opinion in judging the excellence of particular writers is that practically no one looks to reason and weighs the matter in the light of true and settled principles. Indeed everyone in the act of judging embraces a hastily conceived opinion and follows his impressions without reflection or judgment. Thus it is that few have made any attempt so far to arrive at an exact knowledge of the nature of true beauty, by which in the last analysis all else must be determined; rather, each has immediately pronounced that to be beautiful which affected him with some sort of pleasure. Yet there is no norm of judgment more misleading or more variable, for a false and adulterate beauty will give pleasure to minds imbued with deformed opinions whom a true and solid beauty often cannot affect. It follows there is nothing so ugly that it will not please someone or other, and nothing on the other hand so absolutely beautiful that it will not displease someone. Farmers will be found to dance to absurd songs, and whole theaters time and again roar at the tasteless jokes of the actors. Similarly, there are a good many who find little or no delight in Vergil or Terence, though there is nothing in the world of letters more polished--such is the power of custom and preconceived opinion to impart or preclude delight. Consequently, if we wish to dissociate ourselves from the fickle mob of opinions, we must have recourse to reason, which is single, fixed, and simple. We must discover by her aid that true and genuine figure of beauty with which is marked whatever is truly beautiful and finished, and from which whatever departs is justly called ugly and repugnant to taste.