Reason leads us directly to nature and establishes that to be generally beautiful which accords both with the nature of the thing itself and with our own. For example, if an object that is excessive or defective in some part is thought ugly, it is because it diverges from nature which demands a completeness in the parts and despises excess. Almost everything that is judged to be ugly is so judged for the same reason: you will always observe that there is here some flaw at variance with a rightly constituted nature. Nevertheless, for an object to be declared beautiful it is not enough that it answer to its own nature; it must also be congruent with ours. For our nature, being invariable both in the soul and in the body endowed with senses, has definite inclinations and aversions by which it is either attracted or estranged. Thus our eye is moved with pleasure by certain colors, our ear is drawn by a certain kind of sounds; one thing delights the soul, one repels it, each in the measure that it corresponds or is repugnant to our ways of feeling. However, what is meant by nature here is not any nature at all, since some are misshapen, perverse, and corrupt. What is meant is a nature corrected and well-ordered from whose inclinations must arise the judgement of beauty and charm. However, the essence of true beauty is such that it is not fugitive, changeable, or of one time, but rather invariable, fixed, persistent and such as pleases all times equally. And although there may be found some men of so corrupt a nature that they despise beauty, nevertheless they are but few. And even these may be recalled to truth by reason, since false beauty though it may for a while have its admirers cannot long hold them, for nature itself which cannot be erased will gradually beget in them a distaste for it. For, as Cicero so notably says, time that erases the fictions of opinion only confirms the judgements of nature.[1] If we may apply this maxim to literature we may say that that is truly beautiful which agrees both with the nature of things themselves and with the inclinations of our senses and of our soul. And since in a work of literature one takes account of sound, diction, and idea, the agreement of all these with nature in its two aspects is required for beauty. Hence we will take these up one by one, beginning with sound. ON SOUND _How seldom it charms in echoing the sense, how commonly by sweetness. Its natural measure in the ear._