a defect of the stimulus of aliment, and of the understanding and
passions. Their vacant countenances, and their long and disgusting
taciturnity, are the effects of the want of action in their brains from
a deficiency of ideas; and their tranquillity under all the common
circumstances of irritation, pleasure, or grief, are the result of an
absence of passion; for they hold it to be disgraceful to show any
outward signs of anger, joy, or even of domestic affection. This account
of the Indian character, I know, is contrary to that which is given of
it by Rousseau, and several other writers, who have attempted to prove
that man may become perfect and happy without the aids of civilization
and religion. This opinion is contradicted by the experience of all
ages, and is rendered ridiculous by the facts which are well ascertained
in the history of the customs and habits of our American savages. In a
cold climate they are the most miserable beings upon the face of the
earth. The greatest part of their time is spent in sleep, or under the
alternate influence of hunger and gluttony. They moreover indulge in
vices which are alike contrary to moral and physical happiness. It is in
consequence of these habits that they discover so early the marks of old
age, and that so few of them are long-lived. The absence and diminution
of many of the stimuli of life in these people is supplied in part by
the violent exertions with which they hunt and carry on war, and by the
extravagant manner with which they afterwards celebrate their exploits,
in their savage dances and songs.
II. In the inhabitants of the torrid regions of Africa there is a
deficiency of labour; for the earth produces spontaneously nearly all
the sustenance they require. Their understandings and passions are
moreover in a torpid state. But the absence of bodily and mental stimuli
in these people is amply supplied by the constant heat of the sun, by
the profuse use of spices in their diet, and by the passion for musical
sounds which so universally characterises the African nations.
III. In Greenland the body is exposed during a long winter to such a
degree of cold as to reduce the pulse to 40 or 50 strokes in a minute.
But the effects of this cold in lessening the quantity of life are
obviated in part by the heat of close stove rooms, by warm clothing,
and by the peculiar nature of the aliment of the Greenlanders, which
consists chiefly of animal food, of dried fish, and of whale oil. They
prefer the last of those articles in so rancid a state, that it imparts
a f[oe]tor to their perspiration, which, Mr. Crantz says, renders even
their churches offensive to strangers. I need hardly add, that a diet
possessed of such diffusible qualities cannot fail of being highly
stimulating. It is remarkable that the food of all the northern nations
of Europe is composed of stimulating animal or vegetable matters, and
that the use of spiritous liquors is universal among them.
IV. Let us next turn our eyes to the miserable inhabitants of those
eastern countries which compose the Turkish empire. Here we behold life
in its most feeble state, not only from the absence of physical, but of
other stimuli which operate upon the inhabitants of other parts of the
world. Among the poor people of Turkey there is a general deficiency
of aliment. Mr. Volney in his Travels tells us, "That the diet of the
Bedouins seldom exceeds six ounces a day, and that it consists of six
or seven dates soaked in butter-milk, and afterwards mixed with a little
sweet milk, or curds." There is likewise a general deficiency among them
of stimulus from the operations of the mental faculties; for such is
the despotism of the government in Turkey, that it weakens not only the
understanding, but it annihilates all that immense source of stimuli
which arises from the exercise of the domestic and public affections.
A Turk lives wholly to himself. In point of time he occupies only the
moment in which he exists; for his futurity, as to life and property,
belongs altogether to his master. Fear is the reigning principle of his
actions, and hope and joy seldom add a single pulsation to his heart.
Tyranny even imposes a restraint upon the stimulus which arises from
conversation, for "They speak (says Mr. Volney) with a slow feeble
voice, as if the lungs wanted strength to propel air enough through the
glottis to form distinct articulate sounds." The same traveller adds,
that "They are slow in all their motions, that their bodies are small,
that they have small evacuations, and that their blood is so destitute
of serosity, that nothing but the greatest heat can preserve its
fluidity." The deficiency of aliment, and the absence of mental stimuli
in these people is supplied,
1. By the heat of their climate.
2. By their passion for musical sounds and fine clothes. And
3. By their general use of coffee, garlic[98], and opium.
[98] Niebuhr's Travels.
The more debilitated the body is, the more forcibly these stimuli act
upon it. Hence, according to Mr. Volney, the Bedouins, whose slender
diet has been mentioned, enjoy good health; for this consists not
in strength, but in an exact proportion being kept up between the
excitability of the body, and the number and force of the stimuli which
act upon it.
V. Many of the observations which have been made upon the inhabitants
of Africa, and of the Turkish dominions, apply to the inhabitants of
China and the East-Indies. They want, in many instances, the stimulus of
animal food. Their minds are, moreover, in a state too languid to act
with much force upon their bodies. The absence and deficiency of these
stimuli are supplied by,
1. The heat of the climate in the southern parts of those countries.
2. By a vegetable diet abounding in nourishment, particularly rice and
beans.
3. By the use of tea in China, and by a stimulating coffee made of the
dried and toasted seeds of the datura stramonium, in the neighbourhood
of the Indian coast. Some of these nations likewise chew stimulating
substances, as too many of our citizens do tobacco.
Among the poor and depressed subjects of the governments of the
middle and southern parts of Europe, the deficiency of the stimulus
of wholesome food, of clothing, of fuel, and of liberty, is supplied,
in some countries, by the invigorating influence of the christian
religion upon animal life, and in others by the general use of tea,
coffee, garlic, onions, opium, tobacco, malt liquors, and ardent
spirits. The use of each of these stimuli seems to be regulated by the
circumstances of climate. In cold countries, where the earth yields
its increase with reluctance, and where vegetable aliment is scarce,
the want of the stimulus of distension which that species of food is
principally calculated to produce is sought for in that of ardent
spirits. To the southward of 40°, a substitute for the distension from
mild vegetable food is sought for in onions, garlic, and tobacco. But
further, a uniform climate calls for more of these artificial stimuli
than a climate that is exposed to the alternate action of heat and
cold, winds and calms, and of wet and dry weather. Savages and ignorant
people likewise require more of them than persons of civilized manners,
and cultivated understandings. It would seem from these facts that man
cannot exist without _sensation_ of some kind, and that when it is not
derived from natural means, it will always be sought for in such as are
artificial.
In no part of the human species, is animal life in a more perfect state
than in the inhabitants of Great Britain[99], and the United States of
America. With all the natural stimuli that have been mentioned, they
are constantly under the invigorating influence of liberty. There is an
indissoluble union between moral, political, and physical happiness; and
if it be true, that elective and representative governments are most
favourable to individual, as well as national prosperity, it follows of
course, that they are most favourable to animal life. But this opinion
does not rest upon an induction derived from the relation, which truths
upon all subjects bear to each other. Many facts prove animal life to
exist in a larger quantity and for a longer time, in the enlightened
and happy state of Connecticut, in which republican liberty has existed
above one hundred and fifty years, than in any other country upon the
surface of the globe.
[99] Haller's Elements Physiologiæ, vol. viii. p. 2. p. 107.
It remains now to mention certain mental stimuli which act nearly alike
in the production of animal life, upon the individuals of all the
nations in the world. They are,
1. The desire of life. This principle, so deeply and universally
implanted in human nature, acts very powerfully in supporting our
existence. It has been observed to prolong life. Sickly travellers by
sea and land, often live under circumstances of the greatest weakness,
till they reach their native country, and then expire in the bosom of
their friends. This desire of life often turns the scale in favour
of a recovery in acute diseases. Its influence will appear, from the
difference in the periods in which death was induced in two persons,
who were actuated by opposite passions with respect to life. Atticus,
we are told, died of voluntary abstinence from food in five days. In
sir William Hamilton's account of the earthquake at Calabria, we read
of a girl who lived eleven days without food before she expired. In
the former case, life was shortened by an aversion from it; in the
latter, it was protracted by the desire of it. The late Mr. Brissot,
in his visit to this city, informed me, that the application of animal
magnetism (in which he was a believer) had in no instance cured a
disease in a West-India slave. Perhaps it was rendered inert by its
not being accompanied by a strong desire of life; for this principle
exists in a more feeble state in slaves than in freemen. It is possible
likewise the wills and imaginations of these degraded people may have
become so paralytic by slavery, as to be incapable of being excited by
the impression of this fanciful remedy.
2. The love of money sets the whole animal machine in motion. Hearts
which are insensible to the stimuli of religion, patriotism, love,
and even of the domestic affections, are excited into action by this
passion. The city of Philadelphia, between the 10th and 15th of August,
1791, will long be remembered by contemplative men, for having furnished
the most extraordinary proofs of the stimulus of the love of money upon
the human body. A new scene of speculation was produced at that time by
the scrip of the bank of the United States. It excited febrile diseases
in three persons who became my patients. In one of them, the acquisition
of twelve thousand dollars in a few minutes by a lucky sale, brought on
madness which terminated in death in a few days[100]. The whole city
felt the impulse of this paroxysm of avarice. The slow and ordinary
means of earning money were deserted, and men of every profession and
trade were seen in all our streets hastening to the coffee-house, where
the agitation of countenance, and the desultory manners, of all the
persons who were interested in this species of gaming, exhibited a truer
picture of a bedlam, than of a place appropriated to the transaction
of mercantile business. But further, the love of money discovers its
stimulus upon the body in a peculiar manner in the games of cards and
dice. I have heard of a gentleman in Virginia who passed two whole days
and nights in succession at a card table, and it is related in the life
of a noted gamester in Ireland, that when he was so ill as to be unable
to rise from his chair, he would suddenly revive when brought to the
hazard table, by hearing the rattling of the dice.
[100] Dr. Mead relates, upon the authority of Dr. Hales, that more
of the successful speculators in the South-Sea scheme of 1720
became insane, than of those who had been ruined by it.
3. Public amusements of all kinds, such as a horse race, a cockpit, a
chase, the theatre, the circus, masquerades, public dinners, and tea
parties, all exert an artificial stimulus upon the system, and thus
supply the defect of the rational exercises of the mind.
4. The love of dress is not confined in its stimulating operation to
persons in health. It acts perceptibly in some cases upon invalids. I
have heard of a gentleman in South-Carolina, who always relieved himself
of a fit of low spirits by changing his dress; and I believe there are
few people who do not feel themselves enlivened, by putting on a new
suit of clothes.
5. Novelty is an immense source of agreeable stimuli. Companions,
studies, pleasures, modes of business, prospects, and situations, with
respect to town and country, or to different countries, that are _new_,
all exert an invigorating influence upon health and life.
6. The love of fame acts in various ways; but its stimulus is most
sensible and durable in military life. It counteracts in many instances
the debilitating effects of hunger, cold, and labour. It has sometimes
done more, by removing the weakness which is connected with many
diseases. In several instances it has assisted the hardships of a camp
life, in curing pulmonary consumption.
7. The love of country is a deep seated principle of action in the
human breast. Its stimulus is sometimes so excessive, as to induce
disease in persons who recently migrate, and settle in foreign
countries. It appears in various forms; but exists most frequently in
the solicitude, labours, attachments, and hatred of party spirit. All
these act forcibly in supporting animal life. It is because newspapers
are supposed to contain the measure of the happiness or misery of our
country, that they are so interesting to all classes of people. Those
vehicles of intelligence, and of public pleasure or pain, are frequently
desired with the impatience of a meal, and they often produce the same
stimulating effects upon the body[101].
[101] They have been very happily called by Mr. Green, in his poem
entitled Spleen, "the manna of the day."
8. The different religions of the world, by the activity they excite
in the mind, have a sensible influence upon human life. Atheism is
the worst of sedatives to the understanding and passions. It is the
abstraction of thought from the most sublime, and of love from the most
perfect of all possible objects. Man is as naturally a religious, as he
is a social and domestic animal; and the same violence is done to his
mental faculties, by robbing him of a belief in a God, that is done by
dooming him to live in a cell, deprived of the objects and pleasures
of social and domestic life. The necessary and immutable connection
between the texture of the human mind, and the worship of an object of
some kind, has lately been demonstrated by the atheists of Europe, who,
after rejecting the true God, have instituted the worship of nature, of
fortune, and of human reason; and, in some instances, with ceremonies
of the most expensive and splendid kind. Religions are friendly to
animal life, in proportion as they elevate the understanding, and act
upon the passions of hope and love. It will readily occur to you, that
christianity, when believed and obeyed, according to its original
consistency with itself, and with the divine attributes, is more
calculated to produce those effects than any other religion in the
world. Such is the salutary operation of its doctrines and precepts
upon health and life, that if its divine authority rested upon no
other argument, this alone would be sufficient to recommend it to our
belief. How long mankind may continue to prefer substituted pursuits and
pleasures to this invigorating stimulus, is uncertain; but the time, we
are assured, will come, when the understanding shall be elevated from
its present inferior objects, and the luxated passions be reduced to
their original order. This change in the mind of man, I believe, will
be effected only by the influence of the christian religion, after all
the efforts of human reason to produce it, by means of civilization,
philosophy, liberty, and government, have been exhausted to no purpose.
Thus far, gentlemen, we have considered animal life as it respects the
human species; but the principles I am endeavouring to establish require
that we should take a view of it in animals of every species, in all of
which we shall find it depends upon the same causes as in the human body.
And here I shall begin by remarking, that if we should discover the
stimuli which support life in certain animals to be fewer in number,
or weaker in force than those which support it in our species, we
must resolve it into that attribute of the Deity which seems to have
delighted in variety in all his works.
The following observations apply more or less to all the animals upon
our globe.
1. They all possess either hearts, lungs, brains, nerves, or muscular
fibres. It is as yet a controversy among naturalists whether animal life
can exist without a brain; but no one has denied muscular fibres, and of
course contractility, or excitability, to belong to animal life in all
its shapes.
2. They all require more or less air for their existence. Even the snail
inhales it for seven months under ground, through a pellicle which it
weaves out of slime, as a covering for its body. If this pellicle at any
time become too thick to admit the air, the snail opens a passage in it
for that purpose. Now air we know acts powerfully in supporting animal
life.
3. Many of them possess heat equal to that of the human body. Birds
possess several degrees beyond it. Now heat, it was said formerly, acts
with great force in the production of animal life.
4. They all feed upon substances more or less stimulating to their
bodies. Even water itself, chemistry has taught us, affords an aliment,
not only stimulating, but nourishing to many animals.
5. Many of them possess senses, more acute and excitable, than the same
organs in the human species. These expose surfaces for the action of
external impressions, that supply the absence or deficiency of mental
faculties.
6. Such of them as are devoid of sensibility, possess an uncommon
portion of contractility, or simple excitability. This is most evident
in the polypus. When cut to pieces, it appears to feel little or no pain.
7. They all possess loco-motive powers in a greater or less degree, and
of course are acted upon by the stimulus of muscular motion.
8. Most of them appear to feel a stimulus, from the gratification of
their appetites for food, and for venereal pleasures, far more powerful
than that which is felt by our species from the same causes. I shall
hereafter mention some facts from Spalanzani upon the subject of
generation, that will prove the stimulus, from venery, to be strongest
in those animals, in which other stimuli act with the least force. Thus
the male frog during its long connection with its female, suffers its
limbs to be amputated, without discovering the least mark of pain, and
without relaxing its hold of the object of its embraces.
9. In many animals we behold evident marks of understanding and passion.
The elephant, the fox, and the ant exhibit strong proofs of thought; and
where is the school boy that cannot bear testimony to the anger of the
bee and the wasp?
10. But what shall we say of those animals, which pass long winters in
a state in which there is an apparent absence of the stimuli of heat,
exercise, and the motion of the blood. Life in these animals is probably
supported,
1. By such an accumulation of excitability, as to yield to impressions,
which to us are imperceptible.
2. By the stimulus of aliment in a state of digestion in the stomach, or
by the stimulus of aliment restrained from digestion by means of cold;
for Mr. John Hunter has proved by an experiment on a frog, that cold
below a certain degree, checks that animal process.
3. By the constant action of air upon their bodies.
It is possible life may exist in these animals, during their
hybernation, in the total absence of impression and motion of every
kind. This may be the case where the torpor from cold has been
_suddenly_ brought upon their bodies. Excitability here is in an
accumulated, but quiescent state.
11. It remains only under this head to inquire, in what manner is
life supported in those animals which live in a cold element, and
whose blood is sometimes but a little above the freezing point? It
will be a sufficient answer to this question to remark, that heat and
cold are relative terms, and that different animals, according to
their organization, require very different degrees of heat for their
existence. Thirty-two degrees of it are probably as stimulating to some
of these cold blooded animals (as they are called), as 70° or 80° are to
the human body.
It might afford additional support to the doctrine of animal life, which
I have delivered, to point out the manner in which life and growth are
produced in vegetables of all kinds. But this subject belongs to the
professor of botany and natural history[102], who is amply qualified to
do it justice. I shall only remark, that vegetable life is as much the
offspring of stimuli as animal, and that skill in agriculture consists
chiefly in the proper application of them. The seed of a plant, like an
animal body, has no principle of life within itself. If preserved for
many years in a drawer, or in earth below the stimulating influence of
heat, air, and water, it discovers no sign of vegetation. It grows, like
an animal, only in consequence of stimuli acting upon its _capacity_ of
life.
[102] Dr. Barton.
From a review of what has been said of animal life in all its numerous
forms and modifications, we see that it as much an effect of impressions
upon a peculiar species of matter, as sound is of the stroke of a
hammer upon a bell, or music of the motion of the bow upon the strings
of a violin. I exclude therefore the intelligent principle of Whytt,
the medical mind of Stahl, the healing powers of Cullen, and the vital
principal of John Hunter, as much from the body, as I do an intelligent
principle from air, fire, and water.
It is no uncommon thing for the simplicity of causes to be lost in the
magnitude of their effects. By contemplating the wonderful functions of
life we have strangely overlooked the numerous and obscure circumstances
which produce it. Thus the humble but true origin of power in the people
is often forgotten in the splendour and pride of governments. It is
not necessary to be acquainted with the precise nature of that form of
matter, which is capable of producing life from impressions made upon
it. It is sufficient for our purpose to know the fact. It is immaterial,
moreover, whether this matter derives its power of being acted upon
wholly from the brain, or whether it be in part inherent in animal
fibres. The inferences are the same in favour of life being the effect
of stimuli, and of its being as truly mechanical as the movements of a
clock from the pressure of its weights, or the passage of a ship in the
water from the impulse of winds and tide.
The infinity of effects from similar causes, has often been taken
notice of in the works of the Creator. It would seem as if they had
all been made after one pattern. The late discovery of the cause of
combustion has thrown great light upon our subject. Wood and coal are
no longer believed to contain a principle of fire. The heat and flame
they emit are derived from an agent altogether external to them. They
are produced by a matter which is absorbed from the air, by means of
its decomposition. This matter acts upon the predisposition of the
fuel to receive it, in the same way that stimuli act upon the human
body. The two agents differ only in their effects. The former produces
the destruction of the bodies upon which it acts, while the latter
excite the more gentle and durable motions of life. Common language
in expressing these effects is correct, as far as it relates to their
cause. We speak of a coal of fire being _alive_, and of the _flame_ of
life.
The causes of life which I have delivered will receive considerable
support by contrasting them with the causes of death. This catastrophe
of the body consists in such a change induced on it by disease or old
age, as to prevent its exhibiting the phenomena of life. It is brought
on,