I. Whatever is faid to be poffible or impof- fible is expreffisd by a propofition. Now, What is it to conceive a propofition? I think it is no more than to underfland diftinctly its meaning. I know no more that can be meant by fimple apprehenfion or conception, when applied to a propofition. The axiom, there- fore, amounts to this: Every propofition, of which you underftand the meaning diftinclly, is poffible. I am perfuaded, that I underftand as diftindlly the meaning of this propofition. Any twojtdes of a triangle are together equal to the thirds as of this, Any two fides of a triangle are together greater than the third; yet the firft of thefe is impoffiblci Perhaps MISTAKES concerning CONCEPTION. SS Perhaps it will be faid, that though you un-^ HAP. derfland the meaning of the impoffible propo- fition, you cannot fuppofc or conceive it to be true.
Here we are to examine the meaning of the phrafes oi fiippofing and conceiving a propofition to be true. I can certainly fuppofe it to be true, becaufe I can draw confequences from it which I find to be impoffible, as well as the pro- pofition itfehS.
If by conceiving it to be true be meant giv- ing fome degree of afient to it, however fmall, this, I confefs, I cannot do. But will it be faid, that every propofition to which I can give any degree of alTent is poffible? This contra- dicts experience, and therefore the maxim can- not be true in this fenfe.
Sometimes, when we fay that we cannot con^ c^ive a thing to be true, we mean by that ex- preffion, that we Judge it to be impojjible. In this fenfe, I cannot, indeed, conceive it to be true, that two fides of a triangle are equal to the third. I judge it to be impoffible. If, then, we undcritand in this fenfe that maxim, that nothing we can conceive is impoffible, the meaning will be, that nothing is impoffible which we judge to be poinble. But does it not often happen, that what one man judges to be poffible, another man judges to be impoffible? The maxim, therefore, is not true in tiiis fenfe.
1 am not able to find any other meaning of conceiving a propofition^ or of conceiving it to hs true, befides thcfe I have mentioned. 1 know nothing that can be meant by having the idea of a propofition, but either the underflanding its^ meaning, or the judging of its truth. lean underftand S6 ESSAY IV.
C H A P-underftand a proportion that is falfe or impofli- ble, as wei! as one that is true or pofTible; and ^^^'^^I find that men have contradictory judgments about what is pofiible or impoflible, as well as about other things. In what fenfe then can it be faid, that the having an idea of a propor- tion gives certain evidence that it is poffible?
If it be faid, that the idea of a propofition is an image of it in the mind; I think indeed there cannot be a diftind image either in the mind, or elfewhere, of that which is impofli- ble; but what is meant by the image of a pro- pofition I am not able to comprehend, and I fliall be glad to be informed.
2. Every propofition that is neceflarily true, ftands oppofed to a contradictory propofition that is impoffible; and he that conceives one, conceives both: Thus a man who believes that two and three neceflarily make five, mufl be- lieve it to be impoffible that two and three fhould not make five. He conceives both pro- pofitions when he believes one. Every propo- fition carries its contradiftory in its bofom, and both are conceived at the fame time. " It is " confefled, fays Mr. Hume, that in all cafes " where we diflent from any perfon, we con- " ceive both fides of the queflion, but we can " believe only one." From this it certainly follows, that when we diifent from any perfon about a necefiarv propofition, we conceive one that is impoffible; yet I know no Philofopher who has made fo much ufe of the maxim, that whatever we conceive is poffible, as Mr. Hume. A great part of his peculiar tenets is built upon it; and if it is true, they mufl; be true. But he did not perceive, that in the paflage MISTAKES concerning CONCEPTION. 5^: paffage now quoted, the truth of which is evi-C H A P. dent, he contradicts it himfelf. ^^^- ^ :^. Mathematicians have, in many ciifes, pro- ved fome things to be poffible, and others to be impolTible; which, without demonftration, would not have been believed: Yet I have never found, that any Mathematician has at- tempted to prove a thing to be poffible, be- caufe it can be conceived; or impoffible, be- caufe it cannot be conceived. Why is not tliis maxim applied to determine whether it is poffi- ble to fquare the circle? a point about which very eminent Mathematicians have differed. It is eafy to conceive, that in the infinite feries of numbers, and intermediate fradions, fome one number, integral or fractional, may bear the fame ratio to another, as the fide of a fquare bears to its diagonal; yet, however con- ceivable this may be, it may be demonflrated to be impoffible.
4. Mathematicians often require us to con- ceive things that are impoffible, in order to prove them to be fo. This is the cafe in all their demonftrations, ad abfurdiwi. Conceive, fays Euclid, a right line drawn from one point of the circumference of a circle to ano- ther, to fall without the circle; I conceive this, I reafon from it, until I come to a confequence that is manifeftly abfurd; and from thence conclude, that the thing which I conceived is impoffible.
Having faid fo much to fhew, that our pow- er of conceiving a propofition is no criterion of its poffibility or impoffibihty, I ffiall add a few obfervations on the extent of our knowledge of this kind.
I. There CHAP. I. There are many propofitions which, by ^^^- the facukies God has given us, we judge to be neceilary, as well as true. All mathematical propofitions a,re of this kind, and many others. The contradidories of fuch propofitions mud be iinpoffible. Our knowledge, therefore, of what is impoffible, mud at leaft be as exten- five as our knowledge of neceffary truth.
2. By our fenfes, by memory, by teftimony, and by other means, we know many things to be true, which do not appear to be necelfary. But whatever is true, is poffible. Our know- ledge, therefore, of what is poffible, muft at leail extend as far as our knowledge of truth.
3. If a man pretends to determine the poffi- bility or impoffibility of things beyond thefe limits, let him bring proof. I do not fay that no ftich proof can be brought. It has been brought in many cafes, particularly in mathe- matics. But I fay, that his being able to con- ceive a thing, is no proof that it is poffible. Mathematics afford many inftances of impoffi- bilities in the nature of things^ which no man would have believed, if they had not been ftridly demonftrated. Perhaps, if we were able to reafon demonftratively in other fub- jecls, to as great extent as in mathematics, we might find many things to be iinpoffible, which we conclude, without hefitation, to be poffible.
It is poffible, you fay, that God might have made an univerfe of fenfible and rational crea- tures, into which neither natural nor moral evil fhould ever enter. It may be fo, for what I know: But how do you know that it is poffible? That you can conceive it, I grant; but this is no proof. I cannot admit, as an argument, or even as a preffing difficulty, what Of the Train of Thought in the Mind. 5^ what is grounded on the fuppofition that fudi CHAP, a thing is poffible, when there is no good evi- ^^• dence that it is poilible, and, for any thing we "''"' know, it may in the nature of things be im« poffible.
Of ihe 'Train of 'Thought in the Mind.
EVERY man is confcious of a fucceffion. of thoughts which pafs in his mind while he is awake, even when they are not excited by external objefts.
The mind on this account may be compared to liquor in the (late of fermentation. When it is not in this ftate, being once at reft, it remains at reft, until it is moved by fome ex- ternal impulfe. But, in the ftate of fermenta- tion, it has fome caufe of motion in itfelf, which, even when there is no impulfe from without, fuifers it not to be at reft a moment, but produces a cpnftant motion and ebullition, while it continues to ferment.
There is furely no fmiilitude between motion and thought; but there is an analogy, fo ob- vious to all men, that the fame words are often applied to both; and many modifications ot thought have no name but fuch as is borrowed from the modifications of motion. Many thoughts are excited by the fenfes. The cau- fes or occafions of thefe may be confidered as external: But, when fuch external caufes do not operate upon us, we continue to think from fome internal caufe. From the conftitu- tion of the mind itfelf there is a conftant ebul- lition Co ESSAY IV.
C H A P.lltlon of thought, a conftant Inteftine motion; • not only of thoughts barely fpeculative, but of ^'^'"^ fentiments, paffions and afleftions, which at- tend them.
This continued fucceffion of thought has, by modern Philofophers, been called the ima' gination. I think it was formerly called the fancy, or the phantafy. If the old name be laid alide, it were to be wilhed that it had got a name lefs ambiguous than that of imaginati- on, a name which had two or three meanings befides.
It is often called the train of ideas. This may lead one to think that it is a train of bare conceptions; but this would furely be a mif- take. It is made up of many other operations of mind, as well as of conceptions, or ideas.
Memory, judgment, reafoning, paffions, af- feftions and purpofes; in a word, every ope- ration of the mind, excepting thofe of fenfe, is exerted occafionally in this train of thought, and has its fhare as an ingredient: So that we muft take the word idea in a very extenfive fenfe, if v/e make the train of our thoughts to be only a train of ideas.
To pafs from the name, and confider the thing, we may obferve, that the trains of thought in the mind are of two kinds; they are either fuch as flow fpontaneoufly, like wa- ter from a fountain, without any exertion of a governing principle to arrange them; or they are regulated and directed by an adive effort of the mind, with fome view and intention.
Before we confider thefe in their order, it is proper to premife, that thefe two kinds, how- ever diftind in their nature, are for the moil part Of the Train of Thought in the Mind. 6i part mixed, in perfons awake and come toC H A P. years of underftanding. y_^ -.it On the one hand, we are rarely fo vacant of all project and defign, as to let our thoughts take their own courfe, without the leaft check or direction: Or if at any time we fhould be in this flate, fome objed; will prefent itfelf, ■which is too interefting not to engage the at- tention, and roufe the a£live or contemplative powers that were at reft.
On the other hand, when a man is giving the moft intenfe application to any fpeculation, or to any fcheme of condufl:, when he wills to exclude every thought that is foreign, to his prefent purpofe, fuch thoughts will often im- pertinently intrude upon him, in fpite of his endeavours to the contrary, and occupy, by a kind of violence, fome part of the time defti- ned to another purpofe. One man may have the command of his thoughts more than ano- ther man, and the fame man more at one time than at another: But I apprehend, in the beft trained mind the thoughts will fometimes be reftive, fometimes capricious and felf-willed, when wc wifti to have them moft under com- mand.
It has been obferved very juftly, that we muft not afcribe to the mind the power of cal- ling up any thought at pleafure, becaufe fuch a call or volition fuppofes that thought to be already in the mind; for otherwife, how fliould it be the objeQ: of volition? As this muft be granted on the one hand, fo it is no lefs certain on the other, that a man has a con- fiderable power in regulating and difpofmg his own thoughts. Of this every man is confcious.
CHAP, ous, and I can no more doubt of it, than 1 *• can doubt whether I think at all.
We feem to treat the thoughts that prefent themfelves to the fancy in crowds, as a great man treats thofe that attend his levee. They are all ambitious of his attention; he goes round the circle, bellowing a bow upon one, a fmile upon another; afks a (liort queftion of a third; while a fourth is honoured with a particular conference; and the greater part have no particular mark of attention, but go as they came. It is true, he can give no mark of his attention to thofe who were not there, but he has a fufficient number for making a choice and diftinftion.
In like manner, a number of thoughts pre- fent themfelves to the fancy fpontaneoufly j but if we pay no attention to them, nor hold any conference with them, they pafs with the crowd, and are immediately forgot, as if they had never appeared. But thofe to which we think proper to pay attention, may be flopped, examined, and arranged, for any particular purpofe we have in view.
It may Ukewife be obferved, that a train of thought, which was at firfl compofed by appli- cation and judgment, when it has been often repeated, and becomes familiar, will prefent itfelf fpontaneoufly. Thus when a man has compofed an air in mufic, fo as to pleafe his own ear; after he has played, or fung it often, the notes v»'ill arrange themfelves in juft order; and it requires no etfort to regulate their fuc- ceflion.
Thus we fee, that the fancy is made up of trains of thinking; fome of which are fponta- neous, others ftudied and regulated j and the greater Of the Train of Thought in the Mind^ Cr greater part are mixed of both kinds, andCHAP. take their denomination from that which is IV. mod prevalent: And that a train of thought, ' ^~^ which at firfl was ftudied and compofed, may by habit prefent itfelf fpontaneouily. Having -premifed thefe things, let us return to thofe trains of thought which are fpontaneous, which mud be firfl in the order of nature.
When the work of the day is over, and a man lies down to relax his body and mind, he cannot ceafe from thinking, though he defires it. Something occurs to his fancy; that is fol- lowed by another thing, and fo his thoughts are carried on from one obje£t to another, until ileep clofes the fcene.
In this operation of the mind, it is not one faculty only that is employed; there are many that join together in its production. Some- times the tranfactions of the day are brought upon the ftage, and afted over again, as it were, upon this theatre of the imagination. -In this cafe, memory furely acts the mofl con- fiderable part, fmce the fcenes exhibited are •not fidions, but realities, which we remem- ber; yet in this cafe the memory does not a£t alone, other powers are employed, and attend upon their proper objects. The tranfaftions remembered will be more or lefs interefting; and we cannot then review our own conduct, -nor that of others, without paffing fome judg- -ment upon it. This we approve, that we dif- -approve. This elevates, that humbles and de- rpreflfes us. Perfons that are not abfolutely in- ' different to us, can hardly appear, even to the imagination, without fome friendly or un- - friendly emotion. We j udge and reafon about things, as well as perfons in fuch reveries. We remember CHAP, remember what a man faid and did; from this TV ^^/l we pafs to his defigns, and to his general cha- racter, and frame fome hypothefis to make the whole confident. Such trains of thought we may call hiftorical.
There are others which we may call roman- tic, in which the plot is formed by the creative power of fancy, without any regard to what did or will happen. In thefe alio, the powers of judgment, tafle, moral fentiment, as well as the paflions and affeftions, come in and take a fhare in the execution.
In thefe fcenes, the man himfelf commonly a£ts a very diftinguifhed part, and feldom does any thing which he cannot approve. Here the mifer will be generous, the coward brave, and the knave honed. Mr. Addison, in the Spedator, calls this play of the fancy, cadle building.
The young Politician, who has turned his thoughts to the affairs of government, becomes in his imagination a minider of date. He ex- amines every fpring and wheel of the machine of government with the niced eye, and the mod exact judgment. He finds a proper re- medy for every diforder of the commonwealth, quickens trade and manufactures by falutary laws, encourages arts and fciences, and makes the nation happy at home, and refpected abroad. He feels the reward of his good ad- minidration, in that felf-approbation which at- tends it, and is happy in acquiring, by his wife and patriotic conduct, the bleflings of the prefent age, and the praifes of thofe that are to come.
It is probable, that, upon the dage of ima- gination, more great exploits have been per- formed Of the Train of Thought in the Mind. ^^ formed in every age, than have been upon theC M A P. flage of life from the beginning of the v\'orld. ^' • An innate defire of felf-approbation is undoubt- edly a part of the human conllitution. It is a powerful fpur to worthy conduct, and is in- tended as fuch by the Author of our being. A man cannot be eafy or happy, unlefs this defire be in fome meafure gratified. While he conceives himfelf worthlefs and bafe, he can relilh no enjoyment. The humiliating morti- fying fentiment muft be removed, and this na- tural defire of felf-approbation will either pro- duce a noble effort to acquire real worth, which is its proper direQion, or it will lead into fome of thofe arts of felf-deceit, which create a falfe opinion of worth.
A caftle builder in the ficlitioiis fcenesof his fancy, will figure, not according to his real charader, but according to the highefl opinion he has been able to form of himfelf, and per- haps far beyond that opinion. For in thofe imaginary conflicts the paliions eafily yield to reafon, and a man exerts the noblelt efforts of virtue and magnanimity, with the fame eafe, as, in his dreams, he flies through the air, or plunges to the bottom of the ocean.
The romantic fcenes of fancy are mofl com-^ monly the occupation of young minds, not yet fo deeply engaged in life as to have their thoughts taken up by its real cares and bufi- nefs.
Thofe aftive powers of the mind, which are mofl luxuriant by conffcitution, or have been mofl cherifhed by education, impatient to ex- ert themfelves, hurry the thought into fcenes that give them play; and the boy commences in imagination, according to the bent of his Vol. II. F mind, CHAP, mind, a general or a flatefman, a poet or an ^Si^ orator.
When the fair ones become caflle builders, they life different materials; and while the young foldier is carried into the field of Mars, ■where he pierces the thickeft fquadrons of the enemy, defpifmg death in all its forms, the gay and lovely nymph, whofe heart has never felt the tender paffion, is tranfported into a brilliant nlfembly, where flie draws the atten- tion of every eye, and makes an impreflion on the nobleft heart.
But no fooner has Cupid's arrow found Its way into her own heart, than the whole fcenery of her imagination is changed. Balls and alTemblies have now no charms. Woods and groves, the flowery bank, and the cryftal foun- tain, are the fcenes llie frequents in imagina- tion. She becomes an Arcadian fhepherdefs, feeding her flock befide that of her Strephon, and wants no more to complete her happinefs.
In a few years the love-fick maid is trans- formed into the folicitous mother. Her fmi- ling offspring play around her. She views them with a parents eye. Her imagina- tion immediately raifes them to manhood, and brings them forth upon the ftage of life. One ton makes a figure in the army, another fhines 5it the bar; her daughters are happily difpofed of in marriage, and bring new alliances to the family. Her childrcns children rife up before her, and venerate her gray hairs.
Thus the fpontaneous fallies of fancy are as yarious as the cares and fears, the defires and hopes, of man.
Slukquid agiint hom'nus^ voium, tinwr, ira, voluptas, Gaudia, difcurfiis: Thefc Of the Train of Thought in the Mind. 67 Thefe fill up the fcenes of fancy, as well as theC H A p. page of the Satyrift. Whatever pofleffes the ^^• heart makes occafional excurfions into the*^ imagination, and a£ls fuch fcenes upon that theatre as are agreeable to the prevailing palli- on. The man of traffic, who has committed a rich cargo to the inconftant ocean, follows it in his thought; and, according as his hopes or his fears prevail, he is haunted with florms, and rocks, and fliipwreck; or he makes a hap- py and a lucrative voyage; and before his vefTel has loft fight of land, he has difpofed of the profit which fhe is to bring at her return.
The Poet is carried into the Elyfian fields, where he converfes with the ghofts of Homer and Orpheus. The Philofopher makes a tour through the planetary fyftem, or goes down to the centre of the earth, and examines its various flrata. In the devout man likewife, the great objecls that poffefs his heart often play in his imagination j fometimes he is tranf- ported to the regions of the bleffed, from whence he looks down with pity upon the folly and the pageantry of human life; or he prof- trates himfelf before the throne of the Moft High with devout veneration; or he converfes with celeflial fpirits about the natural and mo- ral kingdom of God, which he now fees only by a faint light, but hopes hereafter to view with a fteadier and brighter ray.
In perfons come to maturity, there is even in thefe fpontaneousfallies of fancy, fome arrange- ment of thought; and I conceive that it will be readily allowed, that in thofe who have the greateft ftock of knowledge, and the beft na- tural parts, even the fpontaneous movem.ents of fancy will be the moft regular and connefted. F 2 They C H AP- They have an order, connexion, and unity, ^^- by which they are no lefs diftinguiflied from ^ the dreams of one afleep, or the ravings of one delirious on the one hand, than from the finifhed produ£lions of art on the other.
How is this regular arrangement brought about? It has all the marks of judgment and reafon, yet it feems to go before judgment, and to fpring forth fpontaneoufly.
Shall we beUeve with Leibnitz, that the mind was originally formed like a watch wound up; and that all its thoughts, purpofes, paffi- ons, and adrons, are effefted by the gradual evolution of the original fpring of the machine, and fucceed each other in order, as neceflarily as the motions and pulfations of a watch?
If a child of three or four years, were put to account for the phsenomena of a watch, he would conceive that there is a little man with- in the watch, or fome other little animal, that beats continually, and produces the motion. Whether the hypothecs of this young Philofo- pher in turning the watch fpring into a man, or that of the German Philofopher in turning a man into a \vatch fpring, be the moft ration- al, feems hard to determine.
To account for the regularity of our firfl thoughts, from motions of animal fpirits, vi- brations of nerves, attractions of ideas, or from any other unthinking caufe, whether mechanical or contingent, feems equally irra- tional.
If we be not able to diftinguifli the ftrongefl marks of thought and defign from the effeds of mechanifm or contingency, the confequence will be very melancholy: For it mufl neceflarily follow, that we have no evidence of thought in any Of the Train of Thought in the Mind. 69 any of our fellow men, nay that we have noC H A P, evidence of thought or defign in the ftrufture "^ and government of the univerfe. If a good ' """^ period or fentence was ever produced without having had any judgment previoufly employed about it, why not an Iliad or Eneid? They differ only in lefs and more; and we ihould do injuftice to the Philofopher of Laputa, in laughing at his projeft of making poems by the turning of a wheel, if a concurrence of unthinking caufes may produce a rational train of thought.
It is, therefore, in itfelf highly probable, to fay no more, that whatfoever is regular and rational in a train of thought, which prefents itfelf fpontaneoufly to a man's fancy, without any fludy, is a copy of what had been before compofed by his own rational powers, or thofe of fome other perfon» We certainly judge fo in limilar cafes. Thus, in a book 1 find a train of thinking, which has the marks of knowledge and judgment. I alk how it was produced? It is printed in a book. This does not fatisfy me, becaufe the book has no knowledge nor reafon. I am told that a printer printed it, and a compofitor fet the types. Neither does this fatisfy me. Thefe caufes perhaps knew very little of the fubject. There muft be a prior caufe of the compofiti- on. It was printed from a manufcript. True. But the manufcript is as ignorant as the printed book. The manufcript was written or didla- ted by a man of knowledge and judgment. This, and this only, will fatisfy a man of com- mon underftanding; and it appears to him extremely ridiculous to believe that fuch a train of thinking could originally be produced by any caufe that neither reafons nor thinks.
Whether 70 ESSAY IV.
Whether fuch a train of thinking be printed in a book, or printed, lo to fpeak, in his mind, and ilTue fpontaneoufly from his fancy, it mufl have been compofed with judgment by himfelf, or by fome other rational being.
This, I think, will be confirmed by tracing the progrefs of the human fancy as far back as we are able.
We have not the means of knowing how the fancy is employed in infants. Their time is divided between the employment of their fenfes and found fleep: So that there is little time left for imagination, and the materials it has to work upon are probably very fcanty. A few days after they are born, fometimes a few hours, we fee them fmile in their fleep. But what they fmile at is not eafy to guefs; for they do not fmile at any thing they fee, when awake, for fome months after they are born. It is likewife common to fee them move their lips in fleep, as if they were fucking.
Thefe things feem to difcover fome working of the imagination; but there is no reafon to think that there is any regular train of thought in the mind of infants.
By a regular train of thought, I mean that which has a beginning, a middle, and an end, an arrangement of its parts, according to fome rule, or with fome intention. Thus, the conception of a defign, and of the means of executing it; the conception of a whole, and the number and order of the parts. Thefe are inftances of the mod fmiple trains of thought that can be called regular.
Man has undoubtedly a power (whether we call it tafte or judgment, is not of any confe- quence in the prefent argument) whereby he diflinguilhes Of the Train of Thought in the Mind. 71 diftinguifhes between a compofition, and a^HAP. heap of materials; between a houfe, for in- ^f X-» ftance, and a heap of flones; between a fcn- tence and a heap of words; between a pidure, and a heap of colours. It does not appear to me that children have any regular trains of thought until this power begins to operate. Thofe who are bprn fuch idiots as never to fhew any figns of this power, fhow as little any .iigns of regularity of thought. It feems, there- fore, that this power is connecled with all re- gular trains of thought, and may be the caufc of them.
Such trains of thought difcover themfelves in rhildren about two years of age. They can then give attention to the operations of older children in making their little houfes, and ihips, and other fuch things, in imitation of the works of men. They are then capable of underflanding a little of language, which fliewj; both a regular train of thinking, and fome .degree of abftradio.n. I think wc may per- ceive a diftiniftion between the faculties of children of two or three years of age, and thofe of the moft fagacious brutes. They can then perceive defign and regularity in the works of others, efpecially of older children; their little minds are fired with the difcovery; they are eager.to imitate it, and never at reft till they caa exhibit fomething of the fame kind.
When a child iirft learns by imitation to do fomething that requires defign, how does he exult! Pythagoras was not more happy in the difcovery of his famous theorem. He feems then firft to refiecl upon himfelf, and to fwell with felf-cfteera. His eyes fparkle. He is impatient ro fliew his performance to all about