Appetite.] This moving faculty is the other power of the sensitive soul, which causeth all those inward and outward animal motions in the body. It is divided into two faculties, the power of appetite, and of moving from place to place. This of appetite is threefold, so some will have it; natural, as it signifies any such inclination, as of a stone to fall downward, and such actions as retention, expulsion, which depend not on sense, but are vegetal, as the appetite of meat and drink; hunger and thirst. Sensitive is common to men and brutes. Voluntary, the third, or intellective, which commands the other two in men, and is a curb unto them, or at least should be, but for the most part is captivated and overruled by them; and men are led like beasts by sense, giving reins to their concupiscence and several lusts. For by this appetite the soul is led or inclined to follow that good which the senses shall approve, or avoid that which they hold evil: his object being good or evil, the one he embraceth, the other he rejecteth; according to that aphorism, Omnia appetunt bonum, all things seek their own good, or at least seeming good. This power is inseparable from sense, for where sense is, there are likewise pleasure and pain. His organ is the same with the common sense and is divided into two powers, or inclinations, concupiscible or irascible: or (as one translates it) coveting, anger invading, or impugning. Concupiscible covets always pleasant and delightsome things, and abhors that which is distasteful, harsh, and unpleasant. Irascible, quasi aversans per iram et odium, as avoiding it with anger and indignation. All affections and perturbations arise out of these two fountains, which, although the Stoics make light of, we hold natural, and not to be resisted. The good affections are caused by some object of the same nature; and if present, they procure joy, which dilates the heart, and preserves the body: if absent, they cause hope, love, desire, and concupiscence. The bad are simple or mixed: simple for some bad object present, as sorrow, which contracts the heart, macerates the soul, subverts the good estate of the body, hindering all the operations of it, causing melancholy, and many times death itself; or future, as fear. Out of these two arise those mixed affections and passions of anger, which is a desire of revenge; hatred, which is inveterate anger; zeal, which is offended with him who hurts that he loves; and επιχαιρεχαχια (epichairechachia), a compound affection of joy and hate, when we rejoice at other men's mischief, and are grieved at their prosperity; pride, self-love, emulation, envy, shame, &c., of which elsewhere.
Moving from place to place, is a faculty necessarily following the other. For in vain were it otherwise to desire and to abhor, if we had not likewise power to prosecute or eschew, by moving the body from place to place: by this faculty therefore we locally move the body, or any part of it, and go from one place to another. To the better performance of which, three things are requisite: that which moves; by what it moves; that which is moved. That which moves, is either the efficient cause, or end. The end is the object, which is desired or eschewed; as in a dog to catch a hare. &c. The efficient cause in man is reason, or his subordinate phantasy, which apprehends good or bad objects: in brutes imagination alone, which moves the appetite, the appetite this faculty, which, by an admirable league of nature, and by mediation of the spirit, commands the organ by which it moves; and that consists of nerves, muscles, cords, dispersed through the whole body, contracted and relaxed as the spirits will, which move the muscles, or nerves in the midst of them, and draw the cord, and so per consequens, the joint, to the place intended. That which is moved, is the body or some member apt to move. The motion of the body is divers, as going, running, leaping, dancing, sitting, and such like, referred to the predicament of situs. Worms creep, birds fly, fishes swim; and so of parts, the chief of which is respiration or breathing, and is thus performed. The outward air is drawn in by the vocal artery, and sent by mediation of the midriff to the lungs, which, dilating themselves as a pair of bellows, reciprocally fetch it in, and send it out to the heart to cool it; and from thence now being hot, convey it again, still taking in fresh. Such a like motion is that of the pulse, of which, because many have written whole books, I will say nothing.