in immediate prefence of these types, than 'tis poffible for us to do, merely by an intellectual view and contemplation. Senfible objects have always a greater fluence on the fancy than any other; and this influence they readily convey to those ideas, to which they are related, and which they resemble. I fhall only infer from these practices, and this reafoning, that the effect of resemblance in enlivening the ideas is very common; and as in every cafe a resemblance and a prefent impreffion must concur, we are abundantly fupplied with experiments to prove the reality of the foregoing principle. We may add force to thefe experiments by others of a different kind, in confi. dering the effects of contiguity as well as of resemblance. 'Tis certain that distance diminishes the force of every idea, and that upon our approach to any object; tho' it does not discover itself to our fenfes; it operates upon the mind with an influence, which imitates an immediate impreffion. The thinking on any object readily transports the mind to what is contiguous; but 'tis only the actual prefence of an object, that transports it with a fuperior vivacity. When I am a few miles from home, whatever relates to it touches me more nearly than when I am two hundred leagues diftant; tho' even at that distance the reflecting on any thing in the neighborhood of my friends or family naturally produces an idea of them. But as in this latter cafe, both the objects of the mind are ideas; notwithstanding there is an eafy tranfition betwixt them; that tranfition alone is not able to give a fuperior vivacity to any of the ideas, for want of fome immediate impreffion'. No one can doubt but caufation has the fame influence as the other two relations of resemblance and contiguity. Superftitious people are fond of the relicts of faints and holy men, for the fame reason, that they seek after types or images, in order to enliven their devotion, and give them a more intimate and ftrong conception of thofe exemplary lives, which they defire to imitate. Now 'tis evident, that one of the best relicts, which a devotee could procure, would be the handywork of a faint; and if his cloaths and furniture are ever to be confidered in this light, 'tis because they were once at his difpofal, and were moved and affected by him; in which refpect they are to be confidered as imperfect effects, and as connected with him by a shorter chain of consequences than any of those, by which we learn the reality of his existence. SUPPOSE, that the son of a friend, who had been long dead or absent were prefented to us; 'tis evident, that this object would inftantly revive its correlative idea, and recal to our thoughts all paft intimacies and familiarities in more lively 66 "Naturane nobis, inquit, datum dicam, an errore quodam, ut, cum ea loca videamus, in qui. "bus memoria dignos viros acceperimus multum "effe verfatos, magis moveamur, quam fiquando "eorum ipfo um aut facta audiamus aut fcriptum aliquod legamus? Velut ego nunc moveor. "Venit enim mihi PLATONIS in mentem, quem accepimus primum hîc difputare folitum : Cujus etiam illi ho tuli propinqui non memoriam "folum mihi afferunt, fed ipfum videntur in con"fpectu meo hic ponere. Hic SPEUSIPPUS, hic colors than they would otherwife have appeared to us. This is another phænomenon, which feems to prove the principle above-mentioned. We may obferve, that in thefe phænomena the belief of the correlative object is always pre-fuppofed; without which the relation could have no effect in enlivening the idea. The influence of the picture fuppofes, that we believe our friend to have once exifted. Contiguity to home can never excite our ideas of home, unlefs we believe that it really exifts. Now I affert, that this belief, where it reaches beyond the memory or fenfes, is of a fimilar nature, and arifes from fimilar caufes, with the tranfition of thought and vivacity of conception here explained. When I throw a piece of dry wood into a fire, my mind is immediately carried to conceive, that it augments, not extinguifhes the flame. This tranfition of thought from the cause to the effect proceeds not from reafon. It derives its origin altogether from cuftom and experience. And as it firft begins from an object, prefent to the fenfes, it renders the idea or conception of flame more frong and lively than any loofe, floating reverie of the imagination. That idea arifes immediately. The thought moves inftantly towards it, and conveys to it all that force of conception, which is derived from the impreffion prefent to the fenfes. When a fword is levelled at my breaft, does not the idea of wound and pain ftrike me more strongly, than when a glass of wine is prefented to me, even tho' by accident this idea fhould occur after the appearance of the latter object? But what is there in this whole matter to cause fuch a ftrong conception, except only a prefent object and customary tranfition to the idea of another object, which we have been accustomed to conjoin with the former? This is the whole operation of the mind in all our conclufions concerning matter of fact and existence; and 'tis a fatisfaction to find some analogies, by which it may be explained. The tranfition from a prefent object does in all cafes give ftrength and folidity to the related idea. HERE is a kind of pre-eftablished harmony betwixt the courfe of nature and the fucceffion of our ideas; and tho' the powers and forces, by which the former is governed, be wholly unknown to us; yet our thoughts and conceptions have still, we find, gone on in the fame train with the other works of nature. Cuftom is that admirable principle, by which this correfpondence has been effected; fo neceffary to the fubfiftence of our fpecies, and the regulation of our conduct, in every circumftance and occurrence of human life. Had not the prefence of an object inftantly excited the idea of those objects, commonly conjoined with it, all our knowlege muft have been limited to the narrow sphere of our memory and fenfes; and we fhould never have been able to adjuft means to ends, nor employ our natural powers, either to the producing of good, or avoiding of evil. Thofe, who delight in the difcovery and contemplation of final caufes, have here ample fubject to employ their wonder and admiration. I SHALL add, for a further confirmation of the foregoing theory, that as this cperation of the mind, by which we infer like effects from like caufes, and vice verfa, is fo effential to the fubfiftence of all human creatures, it is not probable that it could be trufted to the fallacious deductions of our reafon, which is flow in its operations; appears not, in any degree, during the firft years of infancy; and at beft is, in every age and period of human life, extremely liable to error and miftake. 'Tis more conformable to the ordinary wisdom of nature to fecure fo neceffary an act of the mind, by fome inftinct or mechanical tendency, which may be be infallible in its operations, may difcover itself at the first appearance of life and thought, and may be independent of all the labored deductions of the understanding. As nature has taught us the ufe of our limbs, without giving us the knowlege of the mufcles and nerves, by which they are actuated; fo has fhe implanted in us an instinct, which carries forward the thought in a correfpondent course to that which she has established among external objects; tho' we are ignorant of thofe powers and forces, on which this regular courfe and fucceffion of objects totally depends. TH HO' there be no fuch thing as Chance in the world; our ignorance of the real cause of any event has the fame influence on the understanding, and begets a like fpecies of belief or opinion. THERE is certainly a probability, which arifes from a fuperiority of chances on any fide; and according as this fuperiority encreafes, and furpaffes the oppofite chances, the probability receives a proportionable encrease, and begets still a higher degree of belief or affent to that fide, in which we difcover the fuperiority. If a dye were marked with one figure or number of spots on four fides, and with another figure or number of fpots on the two remaining fides, it would be more probable, that the former fhould turn up than the latter; tho' if it had a thousand fides marked in the fame manner, and only one fide different, the probability would be much higher, and our belief or expectation of the event more steady and fecure. This process of the thought or reasoning may seem trivial and obvious; but to thofe, who confider it more narrowly, it may, perhaps, afford matter for very curious fpeculations. IT feems evident, that when the mind looks forward to difcover the event, which may refult from the throw of fuch a dye, it confiders the turning up of each particular fide as alike probable; and this is the very nature of chance, to render all the particular events, comprehended in it, entirely equal. But finding a greater number of fides concur in the one event than in the other, the mind is carried more frequently to that event, and meets it oftener, in revolving the va rious poffibilities or chances, on which the ultimate refult depends. This concurrence of feveral views in one particular event begets immediately, by an inexplicable contrivance of nature, the fentiment of belief, and gives that event the advantage over its antagonist, which is fupported by a fmaller number of views, and recurs lefs frequently to the mind. If we allow, that belief is nothing but a Mr. Locke divides all arguments into demonstrative and probable. In this view, we must fay, that 'tis only probable all men must die, or that the fun will rife to morrow. But to conform our language more to common ufe, we should di vide arguments into demonftrations, proofs, and probabilities. By proofs meaning fuch arguments from experience as leave no room for doubt or oppofition. Sf 2 firmer firmer and stronger conception of an object than what attends the mere fictions of the imagination, this operation may, perhaps, in fome measure, be accounted for. The concurrence of these several views or glimpses imprints its idea more ftrongly on the imagination; gives it fuperior force and vigor; renders its influence on the paffions and affections more fenfible; and in a word, begets that reliance or fecurity, which conflitutes the nature of belief and opinion. THE cafe is the fame with the probability of caufes, as with that of chance. There are fome caufes, which are entirely uniform and conftant in producing a particular effect; and no inftance has ever yet been found of any failure or irregularity in their operation. Fire has always burnt, and water fuffocated every human creature: The production of motion by impulfe and gravity is an univerfal law, which has hitherto admitted of no exception. But there are other causes which have been found more irregular and uncertain; nor has rhubarb proved always a purge, or opium a foporific to every one, who has taken these medicines. 'Tis true, when any caufe fails of producing its ufual effect, philofophers afcribe not this to any irregularity in nature; but fuppofe, that fome fecret caufes, in the particular structure of parts, have prevented the operation. Our reasonings, however, and conclufions concerning the event are the fame as if this principle had no place. Being determined by cuftom to transfer the paft to the future, in all our inferences; where the past has been entirely regular and uniform, we expect the event with the greateft affurance, and leave no room for any contrary fuppofition. But where different effects have been found to follow from caufes, which are to appearance exactly fimilar, all these various effects must occur to the mind in transfering the paft to the future, and enter into our confideration, when we determine the probability of the event. Tho' we give the preference to that which has been found moft ufual, and believe that this effect will exift, we must not overlook the other effects, but muft give each of them a particular weight and authority, in proportion as we have found it to be more or lefs frequent. 'Tis more probable, in every place of EUROPE, that there will be frost sometime in JANUARY, than that the weather will continue open thro'out that whole month; tho' this probability varies according to the different climates, and approaches to a certainty in the more northern kingdoms. Here then it seems evident, that when we transfer the past to the future, in order to determine the effect, which will refult from any cause, we tranffer all the different events, in the fame proportion as they have appeared in the paft, and conceive one to have existed a hundred times, for instance, another ten times, and another once. As a great number of views do here concur in one event, they fortify and confirm it to the imagination, beget that sentiment which we call belief, and give it the preference above its antagonist, which is not fupported by an equal number of experiments, and occurs not fo frequently to the thought in transferring the paft to the future. Let any one try to account for this operation of the mind upon any of the received fyftems of philofophy, and he will be fenfible of the difficulty. For my part, I fhall think it fufficient, if the present hints excite the curiofity of philofophers, and make them fenfible how extremely defec tive all common theories are, in treating of such curious and fuch fublime fubjects. SECTION SECTION VII. OF THE IDEA OF NECESSARY CONNEXION. PARTI.. HE great advantage of the mathematical sciences above the moral confifts TH in this, that the ideas of the former, being fenfible, are always clear and determinate, the fmalleft diftinction between them is immediately perceptible, and the fame terms are ftill expreffive of the fame ideas, without ambiguity or variation. An oval is never miftaken for a circle, nor an hyperbola for an ellipfis. The ifofceles and scalenum are distinguished by boundaries more exact than vice and virtue, right and wrong. If any term be defined in geometry, the mind readily, of itself, fubftitutes, on all occafions, the definition for the term defined : Or even when no definition is employed, the object itself may be prefented to the fenfes, and by that means be steadily and clearly apprehended. But the finer fentiments of the mind, the operations of the understanding, the various agitations of the paffions, tho' really in themselves diftinct, easily escape us, when furveyed by reflection; nor is it in our power to recall the original object, as often as we have occafion to contemplate it. Ambiguity, by this means, is gradually introduced into our reafonings: Similar objects are readily taken to be the fame: And the conclufion becomes, at laft, very wide of the premises. ONE may fafely, however, affirm, that, if we confider these sciences in a proper light, their advantages and difadvantages very nearly compenfate each other, and reduce both of them to a state of equality. If the mind with greater facility retains the ideas of geometry clear and determinate, it must carry on a much longer and more intricate chain of reafoning, and compare ideas much wider of each other, in order to reach the abftruser truths of that fcience. And if moral ideas are apt, without extreme care, to fall into obfcurity and confufion, the inferences are always much shorter in thefe difquifitions, and the intermediate fteps, which lead to the conclufion, much fewer than in the fciences, which treat of quantity and number. In reality, there is fcarce a propofition of EUCLID fo fimple as not to confift of more parts, than are to be found in any moral reasoning, which runs not into chimera and conceit. Where we trace the principles of the human mind thro' a few steps, we may be very well fatisfied with our progrefs; confidering how foon nature throws a bar to all our enquiries concerning caufes, and reduces us to an acknowlegement of our ignorance. The chief obftacle, therefore, to our improvement in the moral or metaphyfical fciences is the obfcurity of the ideas, and ambiguity of the terms. The principal difficulty in the mathematics is the length of inferences and compass of thought, requifite to the forming any conclufion. And perhaps, our progrefs in natural philofophy is chiefly retarded by the want of proper experiments and phænomena, which often are difcovered by chance, and cannot always be found, when requifite, even by the moft diligent and prudent enquiry. As moral philofophy feems hitherto to have received lefs improve ments |