As the combs have cells on both fides, the cells may either be exadly oppofite, having partition agalnft partition, or the bot- tom of a cell may reft upon the partitions between the cells on the other fide, which will ferve as a buttrefs to ftrengthen It. The laft way Is beft for ftrength; accordingly, the bottom of each cell refts agalnft the point where three partitions meet on the other fide, which gives it all the ftrength poftible* The The bottom of a cell may either be one plane perpendicular chap. ir. to the fide-partitions, or it may be compofed of feveral planes, meeting in a foliJ angle in the middle point. It is only in one of thefe two ways, that all the cells can be fimilar without lofing room. And, for the fame intention, the planes of which the bottom is compofed, if there be more than one, mufl be three in number, and neither more nor fewer.
It has been demonftrated, that, by making the bottoms of the cells to confift of three planes meeting in a point, there is a faving of material and labour no way inconfiderable. The bees, as if acquainted with thefe principles of folld geometry, follow them mod accurately; the bottom of each cell being compofed of three planes which make obtufe angles with the fide-parti- tions, and with one another, and meet in a point in the middle of the bottom; the three angles of this bottom being fupported by three partitions on the other fide of the comb, and the point of it by the common interfedtion of thofe three partitions.
One inflance more of the mathematical fkill difplayed in the ftruclure of a honey-comb deferves to be mentioned.
It is a curious mathematical problem, at what precife angle the three planes which compofe the bottom of a cell ought to meet, in order to make the greatefl poflible faving, or the leall expence, of material and labour.
. This is one of thofe problems, belonging to the higher parts of mathematics, which are called problems of maxima and mini- ma. It has been refolved by fome mathematicians, particularly by the ingenious Mr Maclaurin, by a fluxionary calculation, which is to be found in the Tranfa(^Ioiis of the Royal Society of London. He has determined precifely the angle required ^ and he found, by the mofl exadt menfuration the fubjed could O 2 admit.
io8 ESSAY III.
CHAP. II. admit, that it is the very angle, in which the three planes in the- bottom of the cell of a honey-comb do actually meet.
Shall we afk here, who taught the bee the properties of folids, and to refolve problems of maxima and minima? If a honey- comb were a work of human art, every man of common fenfe would conclude, without hefitation, that he who invented the conflrudlion, mail have underftood the principles on which it is conflruded.
We need not fay that bees know none of thefe things. They work moft geometrically, without any knowledge of geometry; fomewhat like a child, who, by turning the handle of an organ^ makes good raufic, without any knowledge of mufic.
The art is not in the child, but in him who made the organ. In like manner, when a bee makes its combs fo geometrically, the geometry is not in the bee, but in that great Geometrician who made the bee, and made all things in number, weight and meafure,.
To return to inftinds in man; thofe are mofl remarkable which appear in infancy, when we are ignorant of every thing neceflary to bur prefervation, and therefore mufl; periih, if we had not an invifible Guide, who leads us blind -fold in the way we fliould take, if we had eyes to fee it.
Befides the inftinds which appear only in infancy, and are. intended to fupply the want of underftanding in that early pe- riod, there are many which continue through life, and which fupply the defeds of our intelledual powers in every period. Of thefe we may obferve three clafles.
Firfi^ There are many things neceflary to be done for our pre- fervation, INSTINCT.
fervation, which, even when we will to do, we know not the ci!AP. 11. means by which they inuft be done.
A man knows that he mufl fwallow his food before it can nourifli him. But this adion requires the co-operation of ma- ny nerves and mufclcs, of which he knows nothing; and if it were to be direded folely by his underftanding and will, he would llarve before he learned how to perform it.
Here inftind comes in to his aid. He needs do no more than will to fwallow. All the rcquifite motions of nerves and muf- cles immediately take place in their proper order, without his knowing or willing any thing about them.
If we afk here, whofe will do thefe nerves and mufcles obey? Not his, furely, to whom they belong. He knows neither their names, nor nature, nor office; he never thought of them. They are moved by fome impulfe, of which the caufe is unknown, without any thought, will or intention on his part, that is, they are moved inlHndivelv.
ft ft This is the cafe, in fome degree, in every voluntary motion of our body. Thus, I will to ftretch out my arm. The effedl im- mediately follows. But we know that the arm is ftrctched out by the contradlion of certain mufcles; and that the mufcles are contradled by the influence of the nerves. I know nothing, I think nothing, either of nerves or mufcles, when I ftretch out my arm; yet this nervous influence, and this contraction of the mufcles, uncalled by me, immediately produce the effect which I willed. This is, as if a weight were to be raifed, which can be raifed only by a complication of levers, pullies, and other me- chanical powers, that are behind the curtain, and altogether un- known to me. I will to raife the weight; and no fooner is this volition exerted, than the machinery behind the curtain falls to ■work and raifes the weight.
Tf no ESSAY III.
CHAP. II, If fuch a cafe fiiould happen, we would conclude, that there is fome perfon behind the curtain, who knew my will, and put the machine in motion to execute it.
The cafe of my willing to llretch out my arm, or to fwallow my food, has evidently a great fimilarity to this. But who it is that flands behind the curtain, and fets the internal machinery a-going, is hid from us; fo flrangely and wonderfully are we made. This, however, is evident, that thofe internal motions are nt)t willed nor intended by us, and therefore are iuftindlive.
A fecond cafe in which we have need of inllind, even in ad- vanced life, is. When the adtion muft be fo frequently repeated, that to intend and will it every time it is done, would occupy too much of our thought, and leave no room for other necef- fary employments of the mind.
We muft breathe often every minute whether awake or afleep. We muft often clofe the eye-lids, in order to preferve the luftre of the eye. If thefe things required particular attention and volition every time they are done, they would occupy all our thought. Nature therefore gives an impulfe to do them as often as is neceflary, without any thought at all. They confume no time, they give not the leaft interruption to any exercife of the mind ', becaufe they are done by inftind.
A third cafe, in which we need the aid of inftind, is, When the adion muft be done fo fuddenly, that there is no time to think and determine. When a man lofes his balance, either on foot or on horfeback, he makes an inftantaneous effort to recover it by inftin(5t. The effort would be in vain, if it waited the de- termination of reafon and will.
When.any thing threatens our eyes, we wink hard, by inftindt, and can hardly avoid doing fo, even when we know that the ftroke INSTINCT. Ill flroke is aimed in jeft, and that we are perfedly fafe from dan- CHAP. n.
ger. I liave feen this tried upon a wa52;er, which a man was to gain if he could keep his eyes open, while another aimed a ftroke at them in jefl. The difficulty of doing this fliews that there may be a ftruggle between inflinrt and will; and that it is not eafy to refill; the impulfe of inftinft, even by a ftrong refolution not to yield to it.
Thus the merciful Author of our nature, hath adapted our in- (lindls to the defedts, and to the weaknefs of our underfland- ing. In infancy we are ignorant of every thing j yet many things muft be done by us for our prefervation: Thefe are done by inflind. When we grow up there are many motions of our limbs and bodies necefTary, which can be performed only by a curious and complex internal machinery; a machinery of which the bulk of mankind are totally ignorant, and which the moft fkilful anatomifl knows but imperfedly. All this machinery is fet a-going by inftinc^. We need only to will the external motion, and all the internal motions, previoufly neceffary to the effeft, take place of themfelves, without our will or command.
Some actions muR be fo often repeated, through the whole of life, that, if they required attention and will, we lliould be able to do nothing elfe: Thefe go on regularly by inftincft.
Our prefervation from danger often requires fuch fudden ex- ertions, that there is no time to think and to determine: Accord- ingly we make Inch exertions by inftincft.
Another thing in the nature of man, which I take to be part- ly, though not wholly, iiiflindtive, is his pronenefs to imita- tion.
Aristotle obferved, long ago, that man is an Imitative a- nimal. He is fo in more refpedls than one. He is difpofed to CHAP. 11. to imitate what be approves. In all arts men learn more, and more agreeably, by example than by rules. Imitation by the chifTel, by the pencil, by defcription profaxc and poetical, and by adlion and gefture, have been favourite and elegant enter- tainments of the whole fpecies. In all thefe cafes, however, the imitation is intended and willed, and therefore cannot be faid to be inftindive.
But, I apprehend, that human nature difpofes us to the imita- tion of thofe among whom we live, when we neither defire nor will it.
Let an Englilhman, of middle age, take up his refidence in Edinburgh or Glafgow; although he has not the leaft intention to ufe the Scots dialed, but a firm refolution to preferve his own pure and unmixed, he will find it very difficult to make good his intention. He will, in a courfe of years, fall in- fenfibly, and without intention, into the tone and accent, and even into the words and phrafes of thofe he converfes with j and nothing can preferve him from this, but a flrong difgufl to eve- ry Scoticifm, which perhaps may overcome the natural inflind;.
It is commonly thought that children often learn to flammer by imitation 3 yet I believe no perfon ever defired or willed to learn that quality, I apprehend that inftindive imitation has no fmall influence in forming the peculiarities of provincial dialeds, the peculiari- ties of voice, geflure, and manner, which we fee in fome fami- lies, the manners peculiar to different ranks, and different pro- feflions j and perhaps even in forming national charaders, and the human character in general.
The inflances that hiftory furnifhes of wild men, brought up from early years, without the fociety of any of their own fpe- cies INSTINCT. nj cies are Co few that we cannot build conclufions upon them with CHAP. ir. great certainty. But all I have heard of agreed in this, that the wild man gave but very flender indications of the rational facul- ties; and, with regard to his mind, was hardly diftinguifhable from the more fagacious of the brutes.
There is a confiderable part of the lowcft rank in every na- tion, of whom it cannot be faid that any pains have been taken by themfelves, or by others, to cultivate their underftanding, or to form their manners; yet we fee an immenfe difference between them and the wild man.
This difference is wholly the effedl of foclety; and, I think, it is in a great meafure, though not wholly, the effedt of unde- figned and inftindlive imitation.
Perhaps, not only our adions, but even our judgment, and be- lief, is, in fome cafes, guided by inflindl:, that is, by a natural and blind impulfe.
When we confider man as a rational creature, it may feem right that he fliould have no belief but what is grounded upon evidence, probable or demonllrative; and it is, I think, common- ly taken for granted, that it is always evidence, real or apparent, that determines our belief.
If this be fo, the confequence is, That, in no cafe, can there be any belief, till we find evidence, or, at leaft, what to our judg- ment appears to be evidence. I fufped it is not fo; but that, on the contrary, before we grow up to the full ufe of our rational facul- ties, we do believe, and mufl believe, many things without any evidence at all.
The faculties which we have in common with brute-animals, are of earlier growth than reafon. We are irrational animals P for n+ ESSAY HI.
CHAP. ir. for a conliderable time before we can properly be called rational. The operations of reafon fpring up by imperceptible degrees j nor is it pofllble for vis to trace accurately the order in which they rife. The power of refledtion, by which only we could trace the progrefs of our growing faculties, comes too late to anfvver that end. Some operations of brute-animals look fo like reafon, that they are not eafily diftinguilhed from it. Whether brutes have any thing that can properly be called belief, I cannot fay; but their actions fliew fomething that looks very like it.
If there be any inflincftive belief in man, it is probably of the fame kind with that which we afcribe to brutes, and may be fpe- cifically different from that rational belief which is grounded on evidence; but that there is fomething in man which we call be- lief, which is not grounded on evidence, I think, mufl be granted.
We need to be informed of many things before we ar€ ca- pable of difcerning the evidence on which they reft. W^ere our belief to be with-held till we are capable, in any degree, of weigh- ing evidence, we fhould lofe all the benefit of that inftrudioii and information, without which we could never attain the ufe of our rational faculties.
Man would never acquire the ufe of reafon if he were not brought up in the fociety of reafonable creatures. The benefit he receives from fociety, is derived partly from imitation of what he fees others do, partly from the inftrudlion and informa- tion they communicate to him, without which he could neither be preferved from deftrudtion, nor acquire the ufe of his ration- al powers.
Children have a thoufand things to learn, and they learn ma- ny things every day; more than will be eafily believed by thofe who have never given attention to their progrefs.
Oportet INSTINCT.. f,5 X)portct d'lfcentan credere is a common adage. Clilldrcn liave chap. ir. every thing to learn; and, in order to learn, they mud believe their inftrudors. They need a greater (lock of faiih from in- fancy to twelve or fourteen, than ever after. But how fliall they get this ftock fo nccefifary to tlieni? If their faith de- pend upon evidence, the ftock of evidence, real or apparent, muft bear proportion to their faith. But fuch, in reality, is their fituation, that when their faith mufl be greatell, the evidence is leaft. They believe a thoufand things before they ever fpend a thought upon evidence. Nature fupplies the want of evidence, and gives them an inftindive kind of faith without evidence.
They believe Implicitly whatever they are told, and receive with aflurance the teftimony of every one, without ever thinking of a reafon why they fliould do fo.
A parent or a mafter might command them to believe j but In vain; for belief is not in our power; but in the firft part of life, it is governed by mere teftimony in matters of fad, and by mere authority in all other matters, no lefs than by evidence in riper years.
It is not the words of the teftifier, but his belief, that produces this belief in a child: For children foon learn to diftiii<ruini what is faid in jeft, from what is faid in good earneft. What appears to them to be faid in jeft, produces no belief. They glory in ftiewing that they are not to be impofed on. When the figns of belief in the fpeaker are ambiguous, it is pleafant to ob- ferve with what fagacity they pry into his features, to difcern whether he really believes what he fays, or only counterfeits belief. As foon as this point is determined, their belief is regu- lated by his. if he be doubtful, they are doubtful, if he be af-. fured, they are alfo aflured.
It is well known what a deep impreflion religious principles P 2 zealouflv iifr ESSAY III.
CHAP. II. zealoufly inculcated make upon the minds of children. The abfurditles of ghofts and hobgoblins early imprefled, have been known to flick fo fall, even in enlightened minds, as to baffle all rational conviction.
Wheo we grow up to the ufe of reafon, teftimony attended with certain circumftances, or even authority, may afford a ra- tional ground of belief; but with children, without any regard to circumftances, either of them operates like demonftration. And as they feek no reafon, nor can give any reafon, for this re- gard to teftimony and to authority, it is the effedt of a natural impulfe, and may be called inftindl.
Another inftance of belief which appears to be inftindlive, is that which children fhew even in infancy, that an event v.'hich they have obferved in certain circumftances, will happen again in like circumftances. A child of half a year old, who has once burned his finger by putting it in the candle, will not put it there again. And if you make a fhew of putting it in the candle by force, you fee the mofl manifelt figns that he believes he fhall meet with the fame calamity.
Mr Hume hath fhewn very clearly, that this belief is not the effecft either of reafon or experience. He endeavours to account for it by the affociation of ideas. Though I am not fatisfied with his account of this phenomenon, I fhall not now examine it J becaufe it is fulKcient for the prefent argument, that this be- lief is not grounded on evidence, real or apparent, which I think he clearly proves.
A perfon who has lived fo long In the world, as to obferve that nature is governed by fixed laws, may have fome rational ground to expert fimilar events in fimilar circumftances; but this can- not be the cafe of the child. His belief therefore is not ground- ed on evidence. It is the refult of his conftitution.
Nor Nor is It the lefs fo, though it fliould arifc from the aflbciation CHAP. iii. of ideas. For what is called the alTociation of ideas is a law of nature in our couftitution; which produces its efTcds without any operation of reafon oil our part, and in a manner of wliich we are entirely ignorant.
Of Hahit.
HABIT differs from inftind, not in its nature, but in Its origin.; the latter being natural, the former acquired. Both operate without will or intention, without thought, and therefore may be called mechanical principles.
Habit is commonly defined, A facility of doing a thing, acquired hy having done it frequently. This definition is fufficient for ha- bits of art; but the habits which may, with propriety, be called principles of action, muft give more than a facility, they mufl give aa inclination or impulfe to do the adllon; and that, in many cafes, habits have this force, cannot be doubted.
How many aukward habits, by frequenting Improper compa- ny, are children apt to learn, in their addrefs, motion, looks, gefiure and pronunciation. They acquire fuch habits common- ly from an undefigned and inllindlive iniitation, before they can judge of what is proper and becoming.
When they are a little advanced in undcrflanding, they may eafily be convinced that fuch a thing is unbecoming, they may relolve to forbear it, but when the habit is formed, fuch a gene- ral rcfoluiion is not of itlllf fulficient; for the habit will ope- rate without intention; and particular attention is ncceflary, on every ii8 ESSAY III.
CHAP. III. every occafion, to refift its impulfe, until it be undone by tVie habit of oppofing it.
It is owing to the force of habits, early acquired by imitation, that a man who has grown up to manhood in the lowefl rank of life, if fortune raife him to a higher rank, very rarely acquires the air and manners of a gentleman.
When to that inflindlive imitation, which I fpoke of before, %ve join the force of habit, it is eafy to fee, that thefe mechani- cal principles have no fmall fliare in forming the manners and charader of mort men.
The difficulty of overcoming vicious habits has, in all ages, been a common topic of theologians and moralifls; and we fee too many fad examples to permit us to doubt of it.
There are good habits, in a moral fenfe, as well as bad; and it is certain, that the dated and regular performance of what we approve, not only makes it eafy, bat makes us uneafy in the omilFion of it. This is the cafe, even when the adion dei'ives all its goodnefs from the opinion of the performer. A good il- literate Roman Catholic does not fleep found if he goes to bed without telling his beads, and repeating prayers which he does not underfland.
Aristotle makes wifdom, prudence, good fenfe, fcience and art, as well as the moral virtues and vices, to be habits. If he meaot no more, by giving this name to all thofe intelledual and moral qualities, than that they are all flrengthened and confirm- ed by repeated adls, this is undoubtedly true. I take the word in a lefs extenfive fenfe, when I confider habits as principles of adlion. I conceive it to be a part of our conftitution, that what we have been accuftomed to do, we acquire, not only a facility, but a pronenefs to do on like occafions j fo that it requires a particular particular will and efTort to forbear it, but to do it, requires very CHAPjni. often no will at all. We are carried by habit as by a ftream in fwimming, if we make no refiUance.
Every art furiiiflies examples both of the power of habits and of their utility; no one more than the molt common of all arts, the art of fpeaking.
Articulate language is fpoken, not by nature, but by art. It is no eafy matter to children, to learn the fnnple founds of lan- guage J I mean, to learn to pronounce the vowels and confo- nants. It would be much more difficult, if they were not led by inftind to imitate the founds they hear; for the difficulty is vaflly greater of teaching the deaf to pronounce the letters and words, though experience fliows that it can be done.
What is it that makes this prommciatron fo eafy at lafl which was fo difficult at firft? It is habit.
But from what caufe does it happen, that a good fpeaker no fooner conceives what he would exprefs, than the letters, fylla- blcs and words arrange themfelves according to innumerable rules of fpeech, while he never thinks of thefe rules? He means to exprefs certain fentiments; in order to do this properly, a fe- ledlion muft be made of the materials, out of many thoufands. He makes this feledion without any expence of time or thought. The materials feleded mull be airranged in a particular order, according to innumerable rules of grammar, logic and rhetoric, and accompanied with a particular tone and eniphafis. He does all this as it were by infplration, without thinking of any of thefe rules, and without breaking one of them.
This art, if it were not more common, would appear more wonderful, than that a roan flioukl dance blind-fold amidft a thou land CHAP. Ill, thoufand burning plough-flaares, without being burnt i yet all this may be done by habit.
It appears evident, that as, without infllndl, the infant could not live to become a man, fo, without habit, man would re- main an infant through life, and would be as helplefs, as un- handy, as fpeechlefs, and as much a child in underftanding at threefcore as at three.
I fee no reafon to think, that we fhall ever be able to affign the phyfical caufe, either of inftindl, or of the power of habit.
Both feem to be parts of our original conftitutlon. Their end and ufe is evident; but we can aflign no caufe of them, but the will of him who made us.
With regard to inftindl, which is a natural propenfity, this will perhaps be eafily granted; but it Is no lefs true with regard to that power and inclination which we acquire by habit.
No man can fliew a reafon why our doing a thing frequently fliould produce either facility or inclination to do it.
The fadl is fo notorious, and fo conflantly in our eye, that we are apt to think no reafon fhould be fought for it, any more than why the fun (hines. But there muft be a caufe of the fun's Ibinlng, and there muft be a caufe of the power of habit.
We fee nothing analogous to it in inanimate matter, or in things made by human art. A clock or a watch, a waggon or a plough, by the cuftom of going, does not learn to go better, or require lefs moving force. The earth does not increafe in fertility by the cuftom of bearing crops.
It is faid, that 'trees and other vegetables, by growing long in an an unkindly foil or climate, fometimes acquire qualities by CHAP. in. which they can bear its inclemency with lefs hurt. This, in the vegetable kingdom, has fome refemblancc to the power of ha- bit; but, in inanimate matter, I know nothing that refembles It.
A ftone lofes nothing of its weight by being long fupported, or made to move upward. A body, by being toQed about ever fo long, or ever fo violently, lofes nothing of its inertia, nor ac- quires the leaft difpofition to change its Hate.
H ESSAY III. PART 11.
Of Animal Principles of AElion, Of Appetites.
AVING difcourfed of the mechanical principles of adion, I proceed to confider thofe 1 called animal.
They are fuch as operate upon the will and intention, but do not fuppofe any exercife of judgment or reafon; and are moft of them to be found in fome brute-animals, as well as in man.
In this clafs, the firfl kind I fliall call appetites, taking that word in a ftric^er fenfe than it is fometimes taken, even by good writers.
Q^ The ESSAY in.
CHAP. I. xhe word appetite is fometimes limited, fo as to figt^ify only ' "^ ' the defire of food when we hunger; fometimes it is extended fo as to fignify any ftrong defire, whatever be its obje(ft. With- out pretending to cenfure any ufe of the word which cuflom hath authorifed, I beg leave to limit it to a particular clafs of defires, which are diflinguiflied from all others by the following marks.
Firjl, Every appetite is accompanied with an uneafy fenfation proper to it, which is ftrong or weak, in proportion to the de- fire we have of the objeft. Secondly, Appetites are not conftant, but periodical, beingfated by their objedts for a time, and re- turning after certain periods. Such is the nature of thofe prin- ciples of adlion, to which I beg leave, in this EfTay, to appro- priate the name o? appetites. Thofe that are chiefly obfervable in man, as well as in moft other animals, are hunger, thirft, and luft.
If we attend to the appetite of hunger, we fhall find in it two ingredients, an uneafy fenfuion and a defire to eat. The defire^ keeps pace with the fenfation, and ceafes when it ceafes. When a man is fated with eating, both the uneafy fenfation and the defire to eat ceafe for a time, and return after a certain interval. So it is w^ith other appetites.
In infants, for fome time after they come into the world, the uneafy fenfation of hunger is probably the whole. W^e cannot fuppofe in them, before experience, any conception of eating, nor, confequently, any defire of it. They are led by mere in- ftindl to fuck when they feel the fenfation of hunger. But when experience has conneded, in their imagination, the uneafy fenfation with the means of removing it, the defire of the laft comes to be fo afTociated with the firft, that they remain through life infeparable; And we give the name of hunger to the prin- ciple that is made up of both.
That That the a]:>])ciitL; of hunger includes the two higrcchents I C^HAP. I have nicinionecl will not, I apprehciul, he queftionetl. I take noiice of it the rather becaufe we may, if I niiftake not, find a fnniiar conipolition in other principles of aclion. They arc made up of dilTerent ingredients, and may be analyzed into t]}e parts that enter into their compofition.
If one Philofopher fliould maintain, that hunger is an uneafy fenfation, another, that it is a defire to eat, they feem to difler widely; for a defire and a fenfation are very different things, and have no finiilitude. But they are both in the right j for hunger includes both an- uneafy fenfation and a defire to eat.
Although there has been no fuch difpute among Philofophcrs as we h;ne fuppofed with regard to hunger, yet there have been fimilar difputes with regard to other principles of action; and it deferves to be confidercd whether they may not be terminated in a fimilar manner.
The ends for which our natural appetites are given, are too evident to efcape the obfervation of any man of the lead re- flection. Two of thofe I named are intended for the preferva- tion of the individual, and the third for the continuance of the fpecies.
The reafon of mankind would be altogether infufficient for thcfe ends, without the diredlion and call of apjietite.