There are many things hurtful to life, which are causes of death. One kind is disease. Its beginning is disharmony of the functions, when the simple powers, such as heat, cold, moisture or dryness are excessive or deficient. Then come turns and alterations in the blood, from corruption, and the deterioration of the flesh, when wasting away, should the turns take place according to the changes, to what is acid, or brackish, or bitter, in the blood, or wasting away of the flesh. Hence arise the production of bile, and of phlegm, diseased juices, and the rottenness of liquids weak indeed, unless deeply seated; but difficult to cure, when their commencement is generated from the bones, and painful, if in a state of inflammation of the marrow. The last of disorders are those of the breath, bile and phlegm, when they increase and flow into situations foreign to them, or into places inappropriate for them, by laying hold, of the situation, belonging to what is better, and be driving away what is congenial they fix themselves there, injuring the bodies, and resolving them into the very things.
These then are the sufferings of the body; and hence arise many diseases of the soul; some from one faculty, and some from another. Of the perceptive soul the disease is a difficulty of perception, of the recollecting, a forgetfulness of the appetitive part, a deficiency of desire and eagerness; of the affective, a violent suffering and excited madness; of the rational, an indisposition to learn and think.
But of wickedness the beginnings are pleasure and pains; desires and fears, inflamed by the body, mingled with the wind and called by different names. For there loves and regrets, desires let loose, and passions on the stretch, heavy resentments, and appetites of various kinds, and pleasures immoderate. Plainly, to be unreasonably disposed towards the affections is the limit of virtue, and to be under their rule is that of vice; for to abound in them, or to be superior to them, places us in a good or bad position. Against such impulses the temperaments of our bodies is greatly able to cooperate, whether quick or hot, or various, by leading us to melancholy or violent lewdness; and certain parts, when affected by a catarrh, produce itchings and forms of body more similar to a state of inflammation than one of health; through which a sinking of the spirits and a forgetfulness, a stillness and a state of fear are witnessed.