論人的本性 第 1 章 第 6/9 段

And again, the faculty of sight is a state;

instruments are those things by means of which we act, such as the eye, wealth, and the like.

All the powers of the soul concerned with things good and bad are powers of certain states;

if, then, pleasure is something good or bad, it will exist among these alone;

for otherwise it would not so easily pass over into grief, which is its opposite;

nor is it like that which is opposed to a privation;

for it is impossible for a state and a privation to exist with respect to the same thing at the same time.

Yet some people take pleasure and feel grief at the same time, as do those who scratch themselves;

pleasure, therefore, is not a state.

For instruments exist for the sake of other things, and not for their own sake;

but pleasure exists not for the sake of anything else, but for its own sake;

it remains, then, that it is an activity.

Hence Aristotle defines it as the unimpeded activity of a state that is in accordance with nature.

For the impediments to activity in accordance with nature are grief;

but happiness too is an unimpeded activity of a state that is in accordance with nature;

it follows, then, according to this definition, that happiness would be pleasure, and that the definition is in error;

correcting it, therefore, he defined pleasure as the perfection of the unimpeded activities of the living being that are in accordance with nature, so that pleasure is interwoven with and coexists with happiness, but happiness is not itself pleasure.

Not every activity, however, is a motion; there is also a certain activity that proceeds through immobility, according to which the first God is active;

for the first mover is unmoved.

Of this kind, too, is the activity of contemplation in men.

For both the object contemplated is ever one and the same, and the mind of the one contemplating stands still;

for it is occupied ever about one and the same thing.

And if the pleasure of contemplation—being the greatest, most sovereign, and truest—comes about through immobility, it is clear that those pleasures which come about through fewer motions are, in proportion as they come about through fewer, so much the better and greater.

Pleasures are divided along with activities according to kind; for as many as are the kinds of activities, so many also are the kinds of pleasures;

and the pleasures of noble activities are noble, while those of base ones are base;

and it is clear that with each sense the pleasures also differ in kind.

For those of touch and taste are of one kind, and those of sight, hearing, and smell are of another;

and purer among the senses are those which give pleasure without drawing near to their sensible objects, such as sight, hearing, and smell.

Of the intellectual activities, too, there are two kinds;

for the one is practical, the other contemplative.

It is clear, then, that of the pleasures which accompany these activities there are also two kinds.

And of these the contemplative is purer than the practical.

And proper to man, insofar as he is man, are the intellectual pleasures.

For the sensory pleasures, insofar as he is a living being, are common to him with the other animals.

And since, of the sensory pleasures, some people take pleasure in these, others in those, it is not the ones that appear noble to the base, but the ones that appear noble to the earnest, that are also noble in themselves.

For the right judge in every matter is not just anyone,

but the one who has knowledge and is disposed in accordance with nature.

Of grief there are four kinds: anguish, heaviness, envy, and pity.

Anguish is grief that produces speechlessness;

envy is grief at the good things of others;

Pity is grief over the misfortunes of others.

All grief is an evil by its own nature.

For even the virtuous man will sometimes grieve—when good men are destroyed, or children, or when a city is being sacked;

but not as a primary disposition, nor by deliberate purpose, but only according to circumstance.

And even in these matters the contemplative man will be wholly free from passion, having estranged himself from the things here below and joined himself to God;

while the virtuous man is moderate in his feelings amid them, neither exceeding due measure nor being taken captive by them, but rather mastering them.

Grief is opposed, as an evil to a good, to moderate pleasure; and, as an evil to an evil, to excessive pleasure.

For the contemplative pleasures, being of a supreme kind and possessing perfection, do not admit of excess.

For neither is grief opposed to them, nor do they arise for the healing of a grief that went before them.

On Anger. Anger is a boiling of the blood about the heart, arising from an exhalation of bile or from its being stirred up.

Wherefore it is also called cholē (bile) and cholos (wrath).

And there are times when anger is also a desire for requital.

For when we are wronged, or think ourselves wronged, we grow angry, and then the passion becomes a mixture of desire and anger.

There are three species of the irascible faculty:

wrath (orgē), which is also called cholē and cholos; grudge (mēnis); and rancour (kotos).

For anger, in its beginning and first motion, is called wrath and cholē and cholos;

grudge (mēnis) is bile that is brought to a lasting, aged state;

for it is so named from 'remaining' (menein) and from being committed to memory.

rancour (kotos) is wrath that watches for an opportunity for vengeance;

and this too is so named from 'lying in wait' (keisthai).

Anger is the bodyguard of reason.

For whenever reason judges what has happened to be worthy of indignation, then anger goes forth to punish—provided they keep their proper order according to nature.

On Fear. Fear too is divided into six: into shrinking, into modesty, into shame, into consternation, into astonishment, and into anxiety.

Shrinking (hesitation) is fear of an action about to be undertaken;

consternation is fear arising from a great impression;

astonishment is fear arising from an unaccustomed impression;

anxiety is fear of falling short, that is, of failure;

for fearing to fail in an undertaking, we feel anxiety.

Modesty is fear in the expectation of blame;

and this is a most noble passion.

Shame is fear over a shameful deed already done;

nor is this without hope for salvation.

Modesty differs from shame in this: that he who is ashamed sinks down in dismay over what he has done;

while he who feels modesty fears to fall into some disrepute.

The ancients often call modesty 'shame' and shame 'modesty,' using the names loosely.

Fear arises through a chilling, when all the heat runs together to the heart, to the ruling principle, just as the people, when they are afraid, flee to their rulers.

The organ of grief is the mouth of the stomach.

For this is what perceives the gnawing in griefs, as Galen says in the third book of his Demonstrative treatise, somewhat thus:

'In those who grieve, no small amount of yellow bile flows down into the stomach, which produces the gnawing in them; and they do not cease grieving and being gnawed until they have vomited up the bile.'

For the gnawing occurs in them below the cartilage in the middle of the breastbone, the one called the xiphoid (sword-shaped) process.

But the heart lies much higher up;

for below the diaphragm lies the stomach [while the heart is above it].

It is customary for the ancients to call the mouth of the stomach also 'heart,' as do Hippocrates and Thucydides, who in his account of the plague speaks thus:

'Whenever it settled upon the heart, it turned it over, and all the evacuations of bile that have been named by physicians came on.'

For that which is turned over is the mouth of the stomach, being forced to vomit, not the internal organ, the heart.

On the irrational part that is not obedient to reason. The part that is amenable to reason, then, is of the manner just described.

But to the part that is not persuaded by reason belong the nutritive, the generative, and the pulsatile faculties.

The nutritive and generative are called 'natural,' while the pulsatile is called 'vital.'

On the Nutritive Faculty. The natural powers of the nutritive faculty are four: the attractive, the retentive, the alterative, and the excretory.

For each of the parts of the animal naturally draws to itself its proper nourishment, and having drawn it, retains it; and having retained it, transforms it into itself; and thus expels what is superfluous.

And these are the powers that administer the nourishment of the parts of the body, from which growth, both in length and in breadth, comes about.

The superfluities are excreted through the belly, through the urine, through vomit, through sweat, through the mouth, through the nostrils, through the ears, through the eyes, through exhalation, and through the invisible pores.

Now the other excretions are plainly evident;

but through the ears [is excreted] what is called kypselē, which is the wax of the ears;

through the eyes, tears and rheum (gum);

through exhalation, the sooty residue of the heat of the heart.

And from the contraction of the arteries very many vapours pass out through the porousness of the skin.

The organs of the nutritive faculty are: the mouth, the gullet, the stomach, the liver, all the veins, the intestines, both gall-bladders, and the kidneys.

For the mouth first prepares the food for the stomach, cutting it into small pieces by means of the teeth and the tongue.

For the tongue too renders very great service in mastication, gathering up the food and placing it under the teeth, just as the grinding-women, by means of the hand, place the grain into the mills.

For in a certain manner the tongue too is a hand for mastication.

The food, having thus been worked up, is passed on to the stomach through the gullet;

for the gullet is not only the sense-organ of want (hunger), but also the passage of the food.

For in swallowing it draws upward and pulls in the food and passes it on to the stomach.

The stomach, having received it, separates the useful and nourishing part from the stony and woody and non-nutritive matter;

and changing the useful part into humours, it sends it up to the liver through the veins that draw from it and channel it into the liver—which veins are like roots of the liver, drawing the nourishment from the stomach, just as the roots of plants draw from the earth.

For the stomach is like the earth that supplies nourishment to the plants;

and like roots are the veins that carry up the humour to the portal region and the concave parts of the liver, from the stomach and the intestines, through the mesentery;

and like branches and boughs are the veins that split off from the vena cava (the hollow vein), which grows out from the convex parts of the liver.

For the liver, having received the humour from the stomach, both concocts it and assimilates it to itself.

Since the flesh is most closely akin to the blood, the liver quite naturally transforms the chyle into blood.

The blood is purified by the spleen, the gall-bladder, and the kidneys:

the spleen draws off the dregs and makes of them its own proper nourishment;

the gall-bladder draws off the acrid element that remains in the humours derived from the food;

and the kidneys draw off the watery element together with what remains of the acrid part, so that the blood, having at length become pure and wholesome, may be distributed as nourishment to all the other parts of the body through the veins that are sown throughout them.

And in this way each of the parts, drawing in the blood and retaining it and transforming it into its own nature, passes on the surplus to the neighbouring parts, having become nourishment suitable for them.

And in this manner all the parts are nourished from the blood, and grow, and are maintained, the liver being that which supplies it.

This part is said not to obey reason as belonging to the irrational element, since it accomplishes its own proper work not according to our judgement nor by our free choice, but by nature.

Concerning the pulse. The pulsatile motion is also called the vital faculty.

Having the heart as its origin—and especially its left ventricle, called the pneumatic—it distributes the innate and vital heat to every part of the body through the arteries, just as the liver distributes nourishment through the veins.

Thus when the heart is heated contrary to nature, at once the whole living creature too is heated contrary to nature; and when it is chilled, the creature is chilled.

For the vital spirit is sown from the heart through the arteries into the whole body.

And for the most part these three—vein, artery, and nerve—are branched out alongside one another, from the three principles that govern the living creature:

the nerve from the brain, which is the origin of motion and sensation;

the vein, which is the vessel of the blood, from the liver, which is the origin of blood and of nutrition;

and the artery, which is the vessel of the spirit, from the heart, which is the origin of the vital principle.

And being together with one another, they reap mutual benefits from each other.

For the vein supplies nourishment to the nerve and the artery, while the artery imparts to the vein natural warmth and vital spirit;

whence it is impossible to find an artery without thin blood, or a vein without vaporous spirit.

The artery expands and contracts vigorously according to a certain harmony and proportion, having the origin of its motion from the heart;

and from the adjacent veins it draws by force the thin blood,

which, being vaporized, becomes nourishment for the vital spirit;

and when it contracts, it empties out the sooty matter within it throughout the whole body and through the invisible pores, just as the heart thrusts forth the smoky exhalation in the breathings out, through the mouth and the nose.

Concerning the generative or seminal faculty.

The generative faculty also belongs to the part that does not hearken to reason;

for in dreams we emit the seed without willing it, and the desire for intercourse is natural.

For we are moved toward it even against our will.

But the act itself is admittedly within our power and belongs to the soul;

for it is accomplished through the organs of voluntary motion, and to abstain from and to master the impulse lies within our power.

The organs of the seminal faculty are, first, the veins and the arteries;

for in these the seminal fluid is first produced, the blood being transformed, just as milk is produced in the breasts.

For this humour is the nourishment of these vessels;

for indeed their very origin is from seed.

The arteries and veins, then, concoct the blood into the seminal fluid in order that they may be nourished;

and the surplus of their nourishment becomes seed.

For it is first carried up by a long circuit to the head;

and again from the head it is brought down through two veins and two arteries.

Hence, if one cuts the veins beside the ears and those beside the carotids, one renders the creature barren.

These veins and arteries form the coiled, varicose-like plexus beside the scrotum, where the seminal fluid falls into each of the two testicles—one artery and one vein, full of seed;

and in these it is fully turned into seed, and through the varicose-like epididymis lying behind the testicles it is discharged together with spirit, because that which sends it forth is also an artery.

And that it is also carried from a vein is clear from lechery;

for whenever men have much intercourse and use up the seminal and prolific humour, then, owing to the violent drawing, they discharge pure blood.

Women too have all the same parts as men, but within and not without.

Aristotle, then, and Democritus hold that the seed of the woman contributes nothing to the generation of children;

for they hold that what is emitted from women is a sweat of the part rather than seed.

But Galen, condemning Aristotle, says that women do emit seed, and that the child is formed by the mixture of both seeds;

and that for this reason intercourse is called a 'mixing';

not, however, a perfect seed like that of the man, but one still unconcocted and more fluid.

The woman's seed, being of such a kind, becomes nourishment for the man's.

And from it there is also compacted a certain part of the chorion around the horns of the womb, and what is called the allantois, being a receptacle for the excreta of the embryo.

Now in each kind of animal the female receives the male at the time when she is able to conceive.

Those, therefore, which are always able to conceive always admit intercourse, as do hens and doves and man.

But other creatures, when pregnant, avoid the union;

for hens, laying almost every day, admit intercourse every day;

while women, just as in other matters they have free will, so also have it in intercourse after conception.

For the irrational animals are governed not by themselves but by nature, and they receive fixed measures and a set season.

Another division of the faculties that govern the living creature. They also divide the faculties belonging to the living creature in another way: some they call psychic, some natural, and some vital;

the psychic being those that follow free choice, while the natural and the vital are those that are involuntary.

And there are two psychic faculties: voluntary motion and sensation. Of voluntary motion the species are the faculty of locomotion and of moving the whole body, and the vocal, and the respiratory; for these it lies within us both to do and not to do.

But the natural and vital faculties are those not within our power, but which come to pass both when we are willing and when we are unwilling, such as the nutritive, the augmentative, and the seminal, which are natural;

and the pulsatile, which is vital.

Of voluntary motion we shall now speak.

Concerning the motion which is by impulse or by choice, which belongs to the appetitive faculty. The origin, then, of the motion which is by choice or by impulse is the brain and the spinal marrow, which is itself also a part of the brain;

and the organs are the nerves that grow from these, and the ligaments and the muscles.

The muscles are composed of flesh and sinewy fibres and tendons, interwoven with the fibres of the nerves;

whence some have supposed them to be sensitive, on account of the sensation arising from the nerves interwoven with them.

The tendon, then, is compounded of ligament and thin nerves.

A tendon differs from a nerve in that every nerve is sensitive, round, softer, and has its origin from the brain;

whereas the tendon is both harder, and arises from bone, and is in itself insensible, and is sometimes flat.

The hands are the organ of grasping, and most suited to the arts.

For if one were to take away the hands, or of the hands merely the fingers alone, one would render the man well-nigh useless for almost every art.

Wherefore man alone, inasmuch as he is rational and receptive of the arts, received hands from the Creator.

The feet, however, are an organ of locomotion.

For it is by means of these that we accomplish movement from place to place.

Man alone sits, needing no support.

For he alone bends his legs at two right angles, namely at the hip and at the knee;

the one bending inward, the other outward.

All things, therefore, that are moved by means of sinews and muscles are of the soul and are brought to pass according to choice.

And of these things we have shown both the senses and the voice to be a part.

This, then, is the rational distinction between the works of the soul and those of nature.

But the Creator, according to His supreme forethought, has interwoven the works of the soul with those of nature, and conversely.

For since the discharge of the residues belongs to the excretory faculty, which is one of the natural faculties, in order that we might not involuntarily disgrace ourselves by voiding where we ought not, and when we ought not, and in the presence of those before whom we ought not, He set the muscles as certain gatekeepers over the excretions, and thus made the works of nature to be of the soul.

Accordingly, for this reason we are able to hold back the excretions, both often and for a long time.

The sensory and soft nerves are sent down from the middle and the front ventricles of the brain;

but the harder and motor nerves from the rear ventricle and the spinal marrow;

and those from the spinal marrow are the harder, and of these still harder are those from the lower parts of the spinal marrow.

For the farther the spinal marrow withdraws from the brain, by so much the more does it itself become harder, and so also the nerves that grow out of it.

And just as we received the senses in pairs, so also we have the outgrowths of the nerves in pairs.

For each vertebra of the spine sends forth a pair of nerves, of which the one proceeds to the right parts of the body, the other to the left.

For our whole body is divided, one might say, into two, into right and left.

So too the feet and hands and each of the other members, as also the organs of sense.

Concerning respiration. And breathing too is among the works of the soul.

For it is muscles that dilate the thorax, which is the principal organ of respiration; and the heavy, sighing breathing that arises in times of great grief shows the activity to be of the soul.

And in our power also are the changes of breathing according to need.

For when we feel pain in any of the respiratory parts, or in the parts that move together with them—such as the diaphragm, or the liver, or the spleen, or the belly and the small intestines and the colon—we breathe short and rapidly:

short, that we may not strike the painful part too violently; rapidly, that the density of breaths may make up for what is lacking in their size.

For indeed, when we feel pain in the leg, we extend it but little as we walk, for the same reason for which we do so also with the breathing.

As, therefore, walking too is of the soul, so also is that of breathing.

But it is not possible to hold the breath even for a tenth of an hour.

For the heat within us, being stifled, is quenched by its own soot, and forthwith brings on death.

For indeed, if one were to cover a flame in some vessel that has no vent, one would extinguish it, stifled by its own smoke.

Because of this necessity, therefore, even while we sleep the soul works no less in this respect, knowing that if it should relax even for the briefest moment, the living creature perishes.

Here again, therefore, the natural has been interwoven with that of the soul.

For it accomplishes the activity of respiration by means of an artery—a natural organ and ever in motion—so that its work may never fail, even as neither does that of the other arteries.

Whence some, not understanding, have supposed respiration to be a natural process.

Now there are three causes of respiration: need, faculty, and organs.

The need is twofold: the preservation of the innate heat, and the nourishment of the psychic spirit;

but the preservation of the natural heat is effected both through inhalation and through exhalation:

the inhalation cooling and moderately fanning the heat;

the exhalation pouring out the sooty vapour of the heart.

But the nourishment of the psychic spirit is through respiration alone.

For a certain portion of air is drawn into the heart during its dilations.

For this it is that moves the organs of respiration by means of the muscles, and first of all the thorax.

And with this the lung is moved together, and the rough arteries, which are a part of the lung.

For of the windpipe, the cartilaginous part is the organ of voice, its membranous ligaments the organ of respiration, and that which is composed of both these—the windpipe itself—is an organ both of voice and of respiration.

The lung, then, is a network composed of four things: of the rough artery, and of the smooth vein, and of the frothy flesh of the lung itself, which flesh, like stuffing, fills up the spaces between the network—between the two arteries and the vein—so as to become their seat and bond.

And the flesh of the lung naturally concocts the breath, just as the liver concocts the humour that comes from the belly;

and for this reason, just as the liver embraces with the tips of its lobes the stomach, which is in need of heat, so too the lung encompasses in its midst the heart, which is in need of the cooling that comes from respiration.

And to the windpipe there is joined, in continuity, the bronchus, composed of three great cartilages;

for through both of these we draw in the air from without.

And it passes thence through the sieve-like or spongy bone, which was perforated so that, amid the excesses in the quality of the air, the brain might in no way be harmed when the breath rushes into it in a mass.

And here too the Creator has made use of the nose for both respiration and smell, as of the tongue for voice and taste and mastication.

The parts, then, that are most vital both for existence itself and for the necessary needs of life have been apportioned together with the faculties of the soul.

And if anything has also been passed over, it will be easily discerned from what has already been said.

And just as, of all things that have come into being, some came to be for their own sake, some both for their own sake and for the sake of others, some for the sake of others only, and some came to subsist by accident, so too in the case of the members of the living creature you will find the same sequence.

For all the aforesaid parts, being organs of the three principles that govern the living creature, came to be for their own sake;

for these were constructed primarily and according to the first design—the very things which are properly said to be according to nature—and receive their generation in the womb from the seed itself, as do also the bones.

But the yellow bile is both for its own sake and for the sake of something else.

For it both contributes to digestion and stimulates excretion, and in these respects it becomes in a certain way one of the nutritive parts;

and moreover it also supplies a certain heat to the body, even as the vital faculty does.

For these reasons, then, it seems to have come to be for its own sake;

but by reason of its cleansing the blood, on this account it seems in a certain way to have come to be for the sake of something else.

And the spleen too contributes not a little to digestion.

By pouring the excretion of the superfluous black humour into the belly, it both astringes it and gives it tone and rouses it to digestion.

And in addition to these things it also cleanses the liver.

Wherefore it too seems in a certain way to have come to be for the sake of the blood.

And the kidneys too are a means of cleansing the blood and are the cause of the appetite that pertains to sexual intercourse.

For the veins which we say fall into the testicles pass through the kidneys;

and thence they draw a certain acridity that stirs up the appetite, just as the acridity that arises beneath the skin produces itching.

And by as much as the flesh of the testicles is more tender than the skin, by so much the more, being stung by the acridity, do they render maddening the desire for the emission of the seed.

These things, then, and such as these, have come to be in a certain way both for their own sake and for the sake of other things.

But the glands and the flesh exist only for the sake of other things.

For the glands are a support and prop for the vessels, so that they may not be torn apart when carried suspended amid violent movements.

The flesh, on the other hand, came to be as a covering for the other parts, so that in summer it might cool the living creature by sending forth moisture from within, and in winter might supply it with the service of felted wool.

The skin, too, came to be as a covering both for the tender flesh and for all the other inward parts.

By nature it is flesh that has been hardened into callus both by the surrounding air and by the bodies that come into contact with it.

The bones are the support of the whole body, and above all the spine, which they also say is the keel of the living creature.

The nails, in common with all creatures that possess them, provide the service of scratching, but besides this each also serves a particular use, different in different creatures.

For to many animals they have been given as a means of defence, as to those with hooked talons;

and they are, as it were, an instrument of the spirited part; while to many they serve at once both as a means of defence and as a support for standing, as to horses and to every single-hoofed animal.

And to human beings they serve not only for scratching and for dispersing the acridity of the skin, but also for grasping small objects;

for it is by means of them that we pick up very tiny things.

And by pressing against the tips of the fingers from behind, they steady the grip of the fingers.

The hairs came into being incidentally.

For as the most smoke-like vapours that are sent up from the body take on a certain congealing, they are formed incidentally.

Yet the Creator did not make even these altogether useless;

rather, though they came to be incidentally, He arranged that they should contribute to both shelter and beauty for the living creatures;

shelter for goats and sheep, and adornment for human beings;

and for certain animals both adornment and shelter at once, as for the lion.

On the Voluntary and the Involuntary. Since we have frequently made mention of the voluntary and the involuntary, it is necessary to treat of these matters as well, so that we may not fall short of an exact knowledge of them.

One who intends to speak about the involuntary and the voluntary must first set forth certain rules and criteria by which it will be recognized whether what takes place is voluntary or involuntary.