that every sound in excess, whether acute or grave, perverts the hearing, as every savour in excess does the taste; and every colour over-bright or dark dulls the sight, as every odour excessively pungent, whether grateful or offensive, does the smell, as if shewing that sensibility is a kind of proportion. Thus, qualities, as acid or sweet or saline, are agreeable whenever they are reduced, pure and unmixed, to a due proportion; for it is this only which renders them grateful. To speak generally, harmony is a combination of tones rather than the acute or the grave singly, as for the Touch, the warmed or cooled is genial, rather than the hot or cold, simply; for, as sensibility is proportion, so qualities, in excess, pain or pervert the senses.
Each sense is perceptive of its own appointed subjects, is innate in its own organ, as a special organ, and judges of the distinctions of qualities, as sight judges of white and black; taste of bitter and sweet, and so as to other senses and qualities. But since we judge of white, sweet, and each other quality by its relation to each sense, by what do we perceive that qualities differ? Now, it is evident that it must be by some sense, as the impressions are all sentient; and equally so that the flesh cannot be that final organism, as in order to judge of qualities it must, of necessity, first touch bodies. Neither is it admissible that, by different senses, we judge sweet
