Greek Texts & Translations

Of “smoothness” and “roughness” anyone might be able to discern the causes and explain them also to others. For the cause of the latter is hardness combined with irregularity, and of the former 64aregularity combined with density.

In respect of the affections common to the whole body a very important point, which still remains, is the cause of the pleasures and pains attaching to the sense-affections we have been discussing; and the cause also of those affections which have become perceptible by means of the bodily parts and involve in themselves concomitant pains and pleasures. Let us, then, try to grasp the causes in connection with every perceptible and imperceptible affection in the following way, 64bbearing in mind the distinction we previously drew ^note between mobile and immobile substances; for it is in this way that we must track down all those facts that we intend to grasp. Whenever what is naturally mobile is impressed by even a small affection, it transmits it in a circle, the particles passing on to one another this identical impression until they reach the organ of intelligence and announce the quality of the agent. But a substance of the opposite kind, being stable and having no circular movement, is only affected in itself and does not move any other adjacent particle; consequently, 64csince the particles do not transmit to one another the original affection, it fails to act upon the living creature as a whole, and the result is that the affected body is non-percipient. This is the case with the bones and the hair and all our other parts that are mainly earthy whereas the former character belongs especially to the organs of sight and of hearing, owing to the fact that they contain a very large quantity of fire and air.

Now the nature of pleasure and pain we must conceive of in this way. 64dWhen an affection which is against nature and violent occurs within us with intensity it is painful, whereas the return back to the natural condition, when intense, is pleasant ^note; and an affection which is mild and gradual is imperceptible, while the converse is of a contrary character. And the affection which, in its entirety, takes place with ease is eminently perceptible, but it does not involve pain or pleasure; such, for example, are the affections of the visual stream itself, which, as we said before, ^note becomes in the daylight a body substantially one with our own. For no pains are produced therein by cuttings or burnings 64eor any other affections, nor does its reversion to its original form produce pleasures; but it has most intense and clear perceptions concerning every object that affects it, and every object also which it strikes against or touches; for force is wholly absent both from its dilation and from its contraction. But those bodied which are composed of larger particles, since they yield with difficulty to the agent and transmit their motions to the whole, feel pleasures and pains— 65apains when they suffer alteration, and pleasures when they are restored to their original state. And all those bodies which undergo losses of substance and emptyings that are gradual, but replenishings that are intense and abundant, become insensitive to the emptyings but sensitive to the replenishings; consequently, they furnish no pains to the mortal part of the soul, but the greatest pleasures—a result which is obvious in the case of perfumes. But all those parts which undergo violent alterations, and are restored gradually and with difficulty 65bto their original condition, produce results the opposite of those last mentioned; and it is evident that this is what occurs in the case of burnings and cuttings of the body.

And now we have given a fairly complete statement of the affections which are common to the body as a whole, and of all the names which belong to the agents which produce them. Next we must try, if haply we are able, to describe what takes place in the several parts of our bodies, both the affections themselves and the agents to which they are ascribed.

65cFirstly, then, we must endeavor to elucidate so far as possible those affections which we omitted in our previous account of the flavors, they being affections peculiar to the tongue. It is evident that these also, like most others, are brought about by means of certain contractions and dilations ^note; and, more than other affections, they involve also conditions of roughness and smoothness. For all the earthy particles which enter in by the small veins—which, extending as far as to the heart, serve as it were 65dfor testing-instruments ^note of the tongue,—when they strike upon the moist and soft parts of the flesh and are melted down, contract the small veins and dry them up; and these particles when more rough appear to be” astringent,” when less rough “harsh.” And such as act on these veins as detergents and wash out all the surface of the tongue, when they do this excessively and lay such hold on the tongue as to dissolve part of its substance—and such, for example, is the property of alkalies,—