On Sense And The Sensible   

quality, belong not to every form of the Dry but to the Nutrient, we

shall see by considering that neither the Dry without the Moist, nor

the Moist without the Dry, is nutrient. For no single element, but

only composite substance, constitutes nutriment for animals. Now,

among the perceptible elements of the food which animals assimilate,

the tangible are the efficient causes of growth and decay; it is qua

hot or cold that the food assimilated causes these; for the heat or

cold is the direct cause of growth or decay. It is qua gustable,

however, that the assimilated food supplies nutrition. For all

organisms are nourished by the Sweet [i.e. the 'gustable' proper],

either by itself or in combination with other savours. Of this we must

speak with more precise detail in our work on Generation: for the

present we need touch upon it only so far as our subject here

requires. Heat causes growth, and fits the food-stuff for

alimentation; it attracts [into the organic system] that which is

light [viz. the sweet], while the salt and bitter it rejects because

of their heaviness. In fact, whatever effects external heat produces

in external bodies, the same are produced by their internal heat in

animal and vegetable organisms. Hence it is [i.e. by the agency of

heat as described] that nourishment is effected by the sweet. The

other savours are introduced into and blended in food [naturally] on a

principle analogous to that on which the saline or the acid is used

artificially, i.e. for seasoning. These latter are used because they

counteract the tendency of the sweet to be too nutrient, and to

float on the stomach.

As the intermediate colours arise from the mixture of white and

black, so the intermediate savours arise from the Sweet and Bitter;

and these savours, too, severally involve either a definite ratio,

or else an indefinite relation of degree, between their components,

either having certain integral numbers at the basis of their

mixture, and, consequently, of their stimulative effect, or else being

mixed in proportions not arithmetically expressible. The tastes