 File 28 of a Treatise of Human Nature by David Hume, Volume 1. This LibriVox recording is in the public domain, recording by George Yeager, Book 1, Part 3, Section 13 of Unfilosophical Probability. All these kinds of probability are received by philosophers and allowed to be reasonable foundations of belief and opinion. But there are others that are derived from the same principles, though they have not had the good fortune to obtain the same sanction. The first probability of this kind may be accounted for thus. The diminution of the union and of the resemblance, as above explained, diminishes the facility of the transition. And by that means, weakens the evidence, and we may further observe that the same diminution of the evidence will follow from a diminution of the impression, and from the shading of those colors under which it appears to the memory or senses. The argument which we found on any matter of fact we remember is more or less convincing according as the fact is recent or remote. And though the difference in these degrees of evidence be not received by philosophy as solid and legitimate, because in that case an argument must have a different force today from what it shall have a month hence, yet not withstanding the opposition of philosophy, it is certain this circumstance has a considerable influence on the understanding, and secretly changes the authority of the same argument according to the different times in which it is proposed to us. A greater force and vivacity in the impression naturally conveys a greater to the related idea, and it is on the degrees of force and vivacity that the belief depends according to the foregoing system. There is a second difference which we may frequently observe in our degrees of belief and assurance, and which never fails to take place, though disclaimed by philosophers. An experiment that is recent and fresh in the memory affects us more than one that is in some measure obliterated, and has a superior influence on the judgment as well as on the passions. A lively impression produces more assurance than a faint one, because it has more original force to communicate to the related idea, which thereby acquires a greater force and vivacity. A recent observation has a like effect, because the custom and transition is there more entire, and preserves better the original force in the communication. Thus a drunkard who has seen his companion die of a debauch is struck with that instance for some time, and dreads a like accident for himself. But as the memory of it decays away by degrees, his former security returns, and the danger seems less certain and real. I add as a third instance of this kind that though our reasonings from proofs and from probabilities be considerably different from each other, yet the former species of reasoning often degenerates insensibly into the latter by nothing but the multitude of connected arguments. It is certain that when an inference is drawn immediately from an object, without any intermediate cause or effect, the conviction is much stronger and the persuasion more lively than when the imagination is carried through a long chain of connected arguments, however infallible the connection of each link may be esteemed. It is from the original impression that the vivacity of all the ideas is derived by means of the customary transition of the imagination, and it is evident this vivacity must gradually decay in proportion to the distance and must lose somewhat in each transition. Sometimes this distance has a greater influence than even contrary experiments would have, and a man may receive a more lively conviction from a probable reasoning which is close and immediate than from a long chain of consequences, though just and conclusive in each part. Nay, it is seldom such reasonings produce any conviction, and one must have a very strong and firm imagination to preserve the evidence to the end where it passes through so many stages. But here it may not be amiss to remark a very curious phenomenon which the present subject suggests to us. It is evident there is no point of ancient history of which we can have any assurance but bypassing through many millions of causes and effects, and through a chain of arguments of almost an immeasurable length. Before the knowledge of the fact could come to the first historian, it must be conveyed through many mouths, and after it is committed to writing, each new copy is a new object of which the connection with the foregoing is known only by experience and observation. Perhaps therefore it may be concluded from the precedent reasoning that the evidence of all ancient history must now be lost, or at least will be lost in time, as the chain of causes increases and runs on to a greater length. But as it seems contrary to common sense to think that if the Republic of Letters and the art of printing continue on the same footing as at present, our posterity even after a thousand ages can ever doubt if there has been such a man as Julius Caesar. This may be considered as an objection to the present system. If belief consisted only in a certain vivacity conveyed from an original impression, it would decay by the length of the transition and must at last be utterly extinguished, and vice versa, if belief on some occasions be not capable of such an extinction, it must be something different from that vivacity. Before I answer this objection, I shall observe that from this topic there has been borrowed a very celebrated argument against the Christian religion, but with this difference, that the connection betwixt each link of the chain in human testimony has been there, supposed not to go beyond probability, and to be liable to a degree of doubt and uncertainty. And indeed, it must be confessed that in this manner of considering the subject, which however is not a true one, there is no history or tradition, but what must in the end lose all its force and evidence. Every new probability diminishes the original conviction, and however great that conviction may be supposed, it is impossible it can subsist under such reiterated diminutions. This is true in general, though we shall find, in part four, section one, afterwards, that there is one very memorable exception, which is a vast consequence in the present subject of the understanding. Meanwhile, to give a solution of the preceding objection upon the supposition that historical evidence amounts at first to an entire proof, let us consider that though the links are innumerable that connect any original fact with the present impression, which is the foundation of belief, yet they are all of the same kind and depend on the fidelity of printers and copyists. One addition passes into another, and that into a third, and so on. Till we come to that volume we peruse at present. There is no variation in the steps. After we know one, we know all of them, and after we have made one, we can have no scruple as to the rest. This circumstance alone preserves the evidence of history, and will perpetuate the memory of the present age to the latest posterity. If all the long chain of causes and effects, which connect any past event with any volume of history, were composed of parts different from each other, and which it were necessary for the mind distinctly to conceive, it is impossible we should preserve to the end any belief or evidence. But as most of these proofs are perfectly resembling, the mind runs easily along them, jumps from one part to another with facility, and forms but a confused and general notion of each link. By this means a long chain of argument has as little effect in diminishing the original vivacity as a much shorter would have if composed of parts which were different from each other, and of which each required a distinct consideration. A fourth unphilosophical species of probability is that derived from general rules which we rashly form to ourselves, and which are the source of what we properly call prejudice. An Irishman cannot have wit, and a Frenchman cannot have solidity, for which reason, though the conversation of the former in any instance be visibly very agreeable, and of the latter very judicious, we have entertained such a prejudice against them that they must be dunces or fobs in spite of sense and reason. Human nature is very subject to errors of this kind, and perhaps this nation as much as any other. Should it be demanded why men form general rules and allow them to influence their judgment, even contrary to present observation and experience, I should reply that in my opinion it proceeds from those very principles on which all judgments concerning causes and effects depend. Our judgments concerning cause and effect are derived from habit and experience, and when we have been accustomed to see one object united to another, our imagination passes from the first to the second by a natural transition which precedes reflection and which cannot be prevented by it. Now it is the nature of custom not only to operate with its full force when objects are presented that are exactly the same with those to which we have been accustomed, but also to operate in an inferior degree when we discover such as are similar, and though the habit loses somewhat of its force by every difference, yet it is seldom entirely destroyed where any considerable circumstances remain the same. A man who has contracted a custom of eating fruit by the use of pears or peaches will satisfy himself with melons where he cannot find his favorite fruit. As one who has become a drunkard by the use of red wines will be carried almost with the same violence to white if presented to him. From this principle I have accounted for that species of probability derived from analogy where we transfer our experience in past instances to objects which are resembling but are not exactly the same with those concerning which we have had experience. In proportion as the resemblance decays the probability diminishes, but still has some force as long as there remain any traces of the resemblance. This observation we may carry further and may remark that though custom be the foundation of all our judgments, yet sometimes it has an effect on the imagination in opposition to the judgment and produces a contrarity in our sentiments concerning the same object. I explain myself. In almost all kinds of causes there is a complication of circumstances of which some are essential and others superfluous. Some are absolutely requisite to the production of the effect and others are only conjoined by accident. Now we may observe that when these superfluous circumstances are numerous and remarkable and frequently conjoined with the essential, they have such an influence on the imagination that even in the absence of the latter they carry us on to the conception of the usual effect and give to that conception a force and vivacity which make it superior to the mere fictions of the fancy. We may correct this propensity by a reflection on the nature of those circumstances, but it is still certain that custom takes the start and gives a bias to the imagination. To illustrate this by a familiar instance, let us consider the case of a man who, being hung out from a high tower in a cage of iron, cannot forbear trembling when he surveys the precipice below him, though he knows himself to be perfectly secure from falling by his experience of the solidity of the iron which supports him and though the ideas of fall and descent and harm and death be derived solely from custom and experience. The same custom goes beyond the instances from which it is derived and to which it and to which it perfectly corresponds and influences his ideas of such objects as are in some respect resembling but fall not precisely under the same rule. The circumstances of depth and descent strike so strongly upon him that their influence cannot be destroyed by the contrary circumstances of support and solidity which ought to give him a perfect security. His imagination runs away with its object and excites a passion proportioned to it. That passion returns back upon the imagination and enlivens the idea which lively idea has a new influence on the passion and in its turn augments its force and violence and both his fancy and affections thus mutually supporting each other cause the whole to have a very great influence upon him. But why need we seek for other instances while the present subject of philosophical probabilities offers us so obvious and one in the opposition betwixt the judgment and imagination arising from these effects of custom. According to my system all reasonings are nothing but the effects of custom and custom has no influence but by enlivening the imagination and giving us a strong conception of any object. It may therefore be concluded that our judgment and imagination can never be contrary and that custom cannot operate on the latter faculty after such a manner as to render it opposite to the former. This difficulty we can remove after no other manner than by supposing the influence of general rules. We shall afterwards take in section 15 notice of some general rules by which we ought to regulate our judgment concerning causes and effects. And these rules are formed on the nature of our understanding and on our experience of its operations in the judgments we form concerning objects. By them we learn to distinguish the accidental circumstances from the efficacious causes and when we find that an effect can be produced without the concurrence of any particular circumstance we conclude that that circumstance makes not a part of the efficacious cause however frequently conjoined with it. But as this frequent conjunction necessarily makes it have some effect on the imagination in spite of the opposite conclusion from general rules the opposition of these two principles produces a contrarity in our thoughts and causes us to ascribe the one inference to our judgment and the other to our imagination. The general rule is attributed to our judgment as being more extensive and constant, the exception to the imagination as being more capricious and uncertain. Thus our general rules are in a manner set in opposition to each other. When an object appears that resembles any cause in very considerable circumstances the imagination naturally carries us to a lively conception of the usual effect, though the object be different in the most material and most efficacious circumstances from that cause. Here is the first influence of general rules, but when we take a review of this act of the mind and compare it with the more general and authentic operations of the understanding we find it to be of an irregular nature and destructive of all the most established principles of reasonings which is the cause of our rejecting it. This is a second influence of general rules and implies the condemnation of the former. Sometimes the one, sometimes the other prevails according to the disposition and character of the person. The vulgar are commonly guided by the first and wise men by the second. Meanwhile the skeptics may here have the pleasure of observing a new and signal contradiction in our reason and of seeing all philosophy ready to be subverted by a principle of human nature and again saved by a new direction of the very same principle. The following of general rules is a very unphilosophical species of probability and yet it is only by following them that we can correct this and all other unphilosophical probabilities. Since we have instances where general rules operate on the imagination even contrary to the judgment we need not be surprised to see their effects increase when conjoined with that latter faculty and to observe that they bestow on the ideas they present to us a force superior to what attends any other. Everyone knows there is an indirect manner of insinuating praise or blame which is much less shocking than the open flattery or censure of any person. However he may communicate his sentiments by such secret insinuations and make them known with equal certainty as by the open discovery of them it is certain that their influence is not equally strong and powerful. One who lashes me with concealed strokes of satire moves not my indignation to such a degree as if he flatly told me I was a fool and a coxcomb though I equally understand his meaning as if he did. This difference is to be attributed to the influence of general rules. Whether a person openly abuses me or slightly intimates his contempt in neither case do I immediately perceive his sentiment or opinion and it is only by signs that is by its effects I become sensible of it. The only difference then betwixt these two cases consists in this that in the open discovery of his sentiments he makes use of signs which are general and universal and in the secret intimation employs such as are more singular and uncommon. The effect of this circumstance is that the imagination in running from the present impression to the absent idea makes the transition with greater facility and consequently conceives the object with greater force where the connection is common and universal than where it is more rare and particular. Accordingly we may observe that the open declaration of our sentiments is called the taking off the mask as the secret intimation of our opinions is said to be the veiling of them. The difference betwixt an idea produced by a general connection and that arising from a particular one is here compared to the difference betwixt an impression and an idea. This difference in the imagination has a suitable effect on the passions and this effect is augmented by another circumstance. A secret intimation of anger or contempt shoes that we still have some consideration for the person and avoid the directly abusing him. This makes a concealed satire less disagreeable but still this depends on the same principle. For if an idea were not more feeble when only intimated it would never be esteemed a mark of greater respect to proceed in this method than in the other. Sometimes scurrility is less displeasing than delicate satire because it revenges us in a manner for the injury at the very time it is committed by affording us a just reason to blame and condemn the person who injures us. But this phenomenon likewise depends upon the same principle. For why do we blame all gross and injurious language unless it be because we esteem it contrary to good breeding and humanity? And why is it contrary unless it be more shocking than any delicate satire? The rules of good breeding condemn whatever is openly disobliging and gives a sensible pain and confusion to those with whom we converse. After this is once established abusive language is universally blamed and gives less pain upon account of its coarseness and incivility which render the person despicable that employs it. It becomes less disagreeable merely because originally it is more so and it is more disagreeable because it affords an inference by general and common rules that are palpable and undeniable. To this explication of the different influence of open and concealed flattery or satire I shall add the consideration of another phenomenon which is analogous to it. There are many particulars in the point of honor both of men and women whose violations when open and avowed the world never excuses but which it is more apt to overlook when the appearances are saved and the transgression is secret and concealed. Even those who know with equal certainty that the fault is committed pardon it more easily when the proofs seem in some measure oblique and equivocal than when they are direct and undeniable. The same idea is presented in both cases and properly speaking is equally assented to by the judgment and yet its influence is different because of the different manner in which it is presented. Now if we compare these two cases of the open and concealed violations of the laws of honor we shall find that the difference between them consists in this that in the first case the sign from which we infer the blameable action is single and suffices alone to be the foundation of our reasoning and judgment whereas in the latter the signs are numerous and decide little or nothing when alone and unaccompanied with many minute circumstances which are almost imperceptible but it is certainly true that any reasoning is always the more convincing the more single and united it is to the eye and the less exercise it gives to the imagination to collect all its parts and run from them to the correlative idea which forms the conclusion the labor of the thought disturbs the regular progress of the sentiments as we shall observe presently in part four section one the idea strikes not on us with such vivacity and consequently has no such influence on the passion and imagination from the same principles we may account for those observations of the cardinal derets that there are many things in which the world wishes to be deceived and that it more easily excuses a person in acting than in talking contrary to the decorum of his profession and character a fault in words is commonly more open and distinct than one in actions which admit of many palliating excuses and decide not so clearly concerning the intention and views of the actor thus it appears upon the whole that every kind of opinion or judgment which amounts not to knowledge is derived entirely from the force and vivacity of the perception and that these qualities constitute in the mind what we call the belief of the existence of any object this force and this vivacity are most conspicuous in the memory and therefore our confidence in the veracity of that faculty is the greatest imaginable and equals in many respects the assurance of a demonstration the next degree of these qualities is that derived from the relation of cause and effect and this too is very great especially when the conjunction is found by experience to be perfectly constant and when the object which is present to us exactly resembles those of which we have had experience but below this degree of evidence there are many others which have an influence on the passions and imagination proportioned to that degree of force and vivacity which they communicate to the ideas it is by habit we make the transition from cause to effect and it is from some present impression we borrow that vivacity which we diffuse over the correlative idea but when we have not observed a sufficient number of instances to produce a strong habit or when these instances are contrary to each other or when the resemblance is not exact or the present impression is faint and obscure or the experience in some measure obliterated from the memory or the connection dependent on a long chain of objects or the inference derived from general rules and yet not conformable to them in all these cases the evidence diminishes by the diminution of the force and intenseness of the idea this therefore is the nature of the judgment and probability what principally gives authority to this system is beside the undoubted arguments upon which each part is founded the agreement of these parts and the necessity of one to explain another the belief which attends our memory is of the same nature with that which is derived from our judgments nor is there any difference betwixt that judgment which is derived from a constant and uniform connection of causes and effects and that which depends upon an interrupted and uncertain it is indeed evident that in all determinations where the mind decides from contrary experiments it is first divided within itself and has an inclination to either side in proportion to the number of experiments we have seen and remember this contest is at last determined to the advantage of that side where we observe a superior number of these experiments but still with the diminution of force in the evidence correspondent to the number of the opposite experiments each possibility of which the probability is composed operates separately upon the imagination and it is the larger collection of possibilities which at last prevails and that with a force proportionable to its superiority all these phenomena lead directly to the precedent system nor will it ever be possible upon any other principles to give a satisfactory and consistent explication of them without considering these judgments as the effects of custom on the imagination we shall lose ourselves in perpetual contradiction and absurdity end of file 28 file 29 of a treatise of human nature by david hume volume one this libra vox recording is in the public domain recording by george yeager book one part three section 14 of the idea of necessary connection having thus explained the manner in which we reason beyond our immediate impressions and conclude that such particular causes must have such particular effects we must now return upon our footsteps to examine that question which in section two first occurred to us and which we dropped in our way that is what is our idea of necessity when we say that two objects are necessarily connected together upon this head I repeat what I have often had occasion to observe that as we have no idea that is not derived from an impression we must find some impression that gives rise to this idea of necessity if we assert we have really such an idea in order to this I consider in what objects necessity is commonly supposed to lie and finding that it is always ascribed to causes and effects I turn my eye to two objects supposed to be placed in that relation and examine them in all the situations of which they are susceptible I immediately perceive that they are contiguous in time and place and that the object we call cause precedes the other we call effect in no one instance can I go any farther nor is it possible for me to discover any third relation betwixt these objects I therefore enlarge my view to comprehend several instances where I find like objects always existing in like relations of contiguity and succession at first sight this seems to serve but little to my purpose the reflection on several instances only repeats the same objects and therefore can never give rise to a new idea but upon further inquiry I find that the repetition is not in every particular the same but produces a new impression and by that means the idea which I at present examine for after a frequent repetition I find that upon the appearance of one of the objects the mind is determined by custom to consider its usual attendant and to consider it in a stronger light upon account of its relation to the first object it is this impression then or determination which affords me the idea of necessity I doubt not but these consequences will at first sight be received without difficulty as being evident deductions from principles which we have already established and which we have often employed in our reasonings this evidence both in the first principles and in the deductions may seduce us unwarily into the conclusion and make us imagine it contains nothing extraordinary nor worthy of our curiosity but though such an inadvertence may facilitate the reception of this reasoning it will make it be the more easily forgot for which reason I think it proper to give warning that I have just now examined one of the most sublime questions in philosophy that is that concerning the power and efficacy of causes where all the sciences seem so much interested such a warning will naturally rouse up the attention of the reader and make him desire a more full account of my doctrine as well as of the arguments on which it is founded this request is so reasonable that I cannot refuse complying with it especially as I am hopeful that these principles the more they are examined will acquire the more force and evidence there is no question which on account of its importance as well as difficulty has caused more disputes both among ancient and modern philosophers than this concerning the efficacy of causes or that quality which makes them be followed by their effects but before they entered upon these disputes me thinks it would not have been improper to have examined what ideal we have of that efficacy which is the subject of the controversy this is what I find principally wanting in their reasonings and what I shall hear endeavour to supply I begin with observing that the terms of efficacy agency power force energy necessity connection and productive quality are all nearly synonymous and therefore it is an absurdity to employ any of them in defining the rest by this observation we reject at once all the vulgar definitions which philosophers have given of power and efficacy and instead of searching for the idea in these definitions must look for it in the impressions from which it is originally derived if it be a compound idea it must arise from compound impressions if simple from simple impressions I believe the most general and most popular explication of this matter is to say see mr. Locke chapter of power that finding from experience that there are several new productions in matter such as the motions and variations of body and concluding that there must somewhere be a power capable of producing them we arrive at last by this reasoning at the idea of power and efficacy but to be convinced that this explication is more popular than philosophical we need but reflect on two very obvious principles first that reason alone can never give rise to any original idea and secondly that reason as distinguished from experience can never make us conclude that a cause or productive quality is absolutely requisite to every beginning of existence both these considerations have been sufficiently explained and therefore shall not at present be any further insisted on I shall only infer from them that since reason can never give rise to the idea of efficacy that idea must be derived from experience and from some particular instances of this efficacy which make their passage into the mind by the common channels of sensation or reflection ideas always represent their objects or impressions and vice versa there are some objects necessary to give rise to every idea if we pretend therefore to have any just idea of this efficacy we must produce some instance where in the efficacy is plainly discoverable to the mind and its operations obvious to our consciousness or sensation by the refusal of this we acknowledge that the idea is impossible is impossible and imaginary since the principle of innate ideas which alone can save us from this dilemma has been already refuted and is now almost universally rejected in the learned world our present business then must be to find some natural production where the operation and efficacy of a cause can be clearly conceived and comprehended by the mind without any danger of obscurity or mistake in this research we meet with very little encouragement from that prodigious diversity which is found in the opinions of those philosophers who have pretended to explain the secret force and energy of causes see father malbranche book six part two chapter three and the illustrations upon it there are some who maintain that bodies operate by their substantial form others by their accidents or qualities several by their matter and form some by their form and accidents others by certain virtues and faculties distinct from all this all these sentiments again are mixed and varied in a thousand different ways and form a strong presumption that none of them have any solidity or evidence and that the supposition of an efficacy in any of the known qualities of matter is entirely without foundation this presumption must increase upon us when we consider that these principles of substantial forms and accidents and faculties are not in reality any of the known properties of bodies but are perfectly unintelligible and inexplicable for it is evident philosophers would never have had recourse to such obscure and uncertain principles had they met with any satisfaction in such as are clear and intelligible especially in such an affair as this which must be an object of the simplest understanding if not of the senses upon the whole we may conclude that it is impossible in any one instance to shoe the principle in which the force and agency of a cause is placed and that the most refined and most vulgar understandings are equally at a loss in this particular if anyone think proper to refute this assertion he need not put himself to the trouble of inventing any long reasonings but may at once shoe us an instance of cause where we discover the power or operating principle this defiance we are obliged frequently to make use of as being almost the only means of proving a negative in philosophy the small success which has been met with in all the in all the attempts to fix this power has at last obliged philosophers to conclude that the ultimate force and efficacy of nature is perfectly unknown to us and that it is in vain we search for it in all the known qualities of matter in this opinion they are almost unanimous and it is only in the inference they draw from it that they discover any difference in their sentiments for some of them as the cartesians in particular having established it as a principle that we are perfectly acquainted with the essence of matter have very naturally inferred that it is endowed with no efficacy and that it is impossible for it of itself to communicate motion or produce any of those effects which we ascribe to it as the essence of matter consists in extension and as extension implies not actual motion but only mobility they conclude that the energy which produces the motion cannot lie in the extension this conclusion leads them into another which they regard as perfectly unavoidable matter say they is in itself entirely unactive and deprived of any power by which it may produce or continue or communicate motion but since these effects are evident to our senses and since the power that produces them must be placed somewhere it must lie in the deity or that divine being who contains in his nature all excellency and perfection it is the deity therefore who is the prime mover of the universe and who not only first created matter and gave it its original impulse but likewise by a continued exertion of omnipotence supports its existence and successively bestows on it all those motions and configurations and qualities with which it is endowed this opinion is certainly very curious and well worth our attention but it will appear superfluous to examine it in this place if we reflect a moment on our present purpose in taking notice of it we have established it as a principle that as all ideas are derived from impressions or some precedent perceptions it is impossible we can have any idea of power and efficacy unless some instances can be produced wherein this power is perceived to exert itself now as these instances can never be discovered in body the cartesians proceeding upon their principle of innate ideas have had recourse to a supreme spirit or deity whom they consider as the only active being in the universe and as the immediate cause of every alteration in matter but the principle of innate ideas being allowed to be false it follows that the supposition of a deity can serve us in no stead in accounting for that idea of agency which we search for in vain in all the objects which are presented to our senses or which we are internally conscious of in our own minds for if every idea be derived from an impression the idea of a deity proceeds from the same origin and if no impression either of sensation or reflection implies any force or efficacy it is equally impossible to discover or even imagine any such active principle in the deity since these philosophers therefore have concluded that matter cannot be endowed with any efficacious principle because it is impossible to discover in it such a principle the same course of reasoning should determine them to exclude it from the supreme being or if they esteem that opinion absurd and impious as it really is I shall tell them how they may avoid it and that is by concluding from the very first that they have no adequate idea of power or efficacy in any object since neither in body nor spirit neither in superior nor inferior natures are they able to discover one single instance of it the same conclusion is unavoidable upon the hypothesis of those who maintain the efficacy of second causes and attribute a derivative but a real power and energy to matter for as they confess that this energy lies not in any of the known qualities of matter the difficulty still remains concerning the origin of its idea if we have really an idea of power we may attribute power to an unknown quality but as it is impossible that that idea can be derived from such a quality and as there is nothing in known qualities which can produce it it follows that we deceive ourselves when we imagine we are possessed of any idea of this kind after the manner we commonly understand it all ideas are derived from and represent impressions we never have any impression that contains any power or efficacy we never therefore have any idea of power some have asserted that we feel an energy or power in our own mind and that having in this manner acquired the idea of power we transfer that quality to matter where we are not able immediately to discover it the motions of our body and the thoughts and sentiments of our mind say they obey the will nor do we seek any further to acquire a just notion of force or power but to convince us how fallacious this reasoning is we need only consider that the will being here considered as a cause has no more a discoverable connection with its effects than any material cause has with its proper effect so far from perceiving the connection betwixt an act of volition and the motion of the body it is allowed that no effect is more inexplicable from the powers and essence of thought and matter nor is the empire of the will over our mind more intelligible the effect is there distinguishable and separable from the cause and could not be foreseen without the experience of their constant conjunction we have command over our mind to a certain degree but beyond that lose all empire over it and it is evidently impossible to fix any precise bounds to our authority where we consult not experience in short the actions of the mind are in this respect the same with those of matter we perceive only their constant conjunction nor can we ever reason beyond it no internal impression has an apparent energy more than external objects have since therefore matter is confessed by philosophers to operate by an unknown force we should in vain hope to attain an idea of force by consulting our own minds footnote eight the same imperfection attends our ideas of the deity but this can have no effect either on religion or morals the order of the universe proves an omnipotent mind that is a mind whose will is constantly attended with the obedience of every creature and being nothing more is requisite to give a foundation to all the articles of religion nor is it necessary we should form a distinct idea of the force and energy of the supreme being and a footnote eight it has been established as a certain principle that general or abstract ideas are nothing but individual ones taken in a certain light and that in reflecting on any object it is as impossible to exclude from our thought all particular degrees of quantity and quality as from the real nature of things if we be possessed therefore of any idea of power in general we must also be able to conceive some particular species of it and as power cannot subsist alone but is always regarded as an attribute of some being or existence we must be able to place this power in some particular being and conceive that being as endowed with a real force and energy by which such a particular effect necessarily results from its operation we must distinctly and particularly conceive the connection betwixt to cause and effect and be able to pronounce from a simple view of the one that it must be followed or preceded by the other this is the true matter of conceiving a particular power in a particular body and a general idea being impossible without an individual where the latter is impossible it is certain the former can never exist now nothing is more evident than that the human mind cannot form such an idea of two objects as to conceive any connection betwixt them or comprehend distinctly that power or efficacy by which they are united such a connection would amount to a demonstration and would imply the absolute impossibility for the one object not to follow or to be conceived not to follow upon the other which kind of connection has already been rejected in all cases if any one is of a contrary opinion and thinks he has attained a notion of power in any particular object I desire he may point out to me that object but till I meet with such a one which I despair of I cannot forbear concluding that since we can never distinctly conceive how any particular power can possibly reside in any particular object we deceive ourselves in imagining we can form any such general idea thus upon the whole we may infer that when we talk of any being whether of a superior or inferior nature as endowed with a power or force proportion to any effect when we speak of a necessary connection betwixt objects and suppose that this connection depends upon an efficacy or energy with which any of these objects are endowed in all these expressions so applied we have really no distinct meaning and make use only of common words without any clear and determinant ideas but as it is more probable that these expressions do here lose their true meaning by being wrong applied then that they never have any meaning it will be proper to bestow another consideration on this subject to see if possibly we can discover the nature and origin of those ideas we annex to them suppose two objects to be presented to us of which the one is the cause and the other the effect it is plain that from the simple consideration of one or both these objects we never shall perceive the tie by which they are united or be able certainly to pronounce that there is a connection betwixt them it is not therefore from any one instance that we arrive at the idea of cause and effect of a necessary connection of power of force of energy and of efficacy did we never see any but particular conjunctions of objects entirely different from each other we should never be able to form any such ideas but again suppose we observe several instances in which the same objects are always conjoined together we immediately conceive a connection betwixt them and began to draw an inference from one to another this multiplicity of resembling instances therefore constitutes the very essence of power or connection and is the source from which the idea of it arises in order then to understand the idea of power we must consider that multiplicity nor do i ask more to give a solution of that difficulty which has so long perplexed us for thus i reason the repetition of perfectly similar instances can never alone give rise to an original idea different from what is to be found in any particular instance as has been observed and as evidently follows from our fundamental principle that all ideas are copied from impressions since therefore the idea of power is a new original idea not to be found in any one instance and which yet arises from the repetition of several instances it follows that the repetition alone has not that effect but must either discover or produce something new which is the source of that idea did the repetition neither discover nor produce anything new our ideas might be multiplied by it but would not be enlarged above what they are upon the observation of one single instance every enlargement therefore such as the idea of power or connection which arises from the multiplicity of similar instances is copied from some effects of the multiplicity and will be perfectly understood by understanding these effects wherever we find anything new to be discovered or produced by the repetition there we must place the power and must never look for it in any other object but it is evident in the first place that the repetition of like objects in like relations of succession and contiguity discovers nothing new in any one of them since we can draw no inference from it nor make it a subject either of our demonstrative or probable reasonings c section six as has been already proved nay suppose we could draw an inference it would be of no consequence in the present case since no kind of reasoning can give rise to a new idea such as this of power is but wherever we reason we must antecedently be possessed of clear ideas which may be the objects of our reasoning the conception always precedes the understanding and where the one is obscure the other is uncertain where the one fails the other must fail also secondly it is certain that this repetition of similar objects in similar situations produces nothing new either in these objects or in any external body for it will readily be allowed that the several instances we have of the conjunction of resembling causes and effects are in themselves entirely independent and that the communication of motion which I see result at present from the shock of two billiard balls is totally distinct from that which I saw result from such an impulse a twelve month ago these impulses have no influence on each other they are entirely divided by time and place and the one might have existed and communicated motion though the other never had been in being there is then nothing new either discovered or produced in any objects by their constant conjunction and by the uninterrupted resemblance of their relations of succession and contiguity but it is from this resemblance that the ideas of necessity of power and of efficacy are derived these ideas therefore represent not anything that does or can belong to the objects which are constantly conjoined this is an argument which in every view we can examine it will be found perfectly unanswerable similar instances are still the first source of our idea of power or necessity at the same time that they have no influence by their similarity either on each other or on any external object we must therefore turn ourselves to some other quarter to seek the origin of that idea though the several resembling instances which give rise to the idea of power have no influence on each other and can never produce any new quality in the object which can be the model of that idea yet the observation of this resemblance produces a new impression in the mind which is its real model for after we have observed the resemblance in a sufficient number of instances we immediately feel a determination of the mind to pass from one object to its usual attendant and to conceive it in a stronger light upon account of that relation this determination is the only effect of the resemblance and therefore must be the same with power or efficacy whose idea is derived from the resemblance the several instances of resembling conjunctions lead us into the notion of power and necessity these instances are in themselves totally distinct from each other and have no union but in the mind which observes them and collects their ideas necessity then is the effect of this observation and is nothing but an internal impression of the mind or a determination to carry our thoughts from one object to another without considering it in this view we can never arrive at the most distant notion of it or be able to attribute it either to external or internal objects to spirit or body to causes or effects the necessary connection betwixt causes and effects is the foundation of our inference from one to the other the foundation of our inference is the transition arising from the accustomed union these are therefore the same the idea of necessity arises from some impression there is no impression conveyed by our senses which can give rise to that idea it must therefore be derived from some internal impression or impression of reflection there is no internal impression which has any relation to the present business but that propensity which custom produces to pass from an object to the idea of its usual attendant this therefore is the essence of necessity upon the whole necessity is something that exists in the mind not in objects nor is it possible for us ever to form the most distant idea of it considered as a quality in bodies either we have no idea of necessity or necessity is nothing but that determination of the thought to pass from causes to effects and from effects to causes according to their experienced union thus as the necessity which makes two times two equal to four or three angles of a triangle equal to two right ones lies only in the act of the understanding by which we consider and compare these ideas in like manner the necessity or power which unites causes and effects lies in the determination of the mind to pass from the one to the other the efficacy or energy of causes is neither placed in the causes themselves nor in the deity nor in the concurrence of these two principles but belongs entirely to the soul which considers the union of two or more objects in all past instances it is here that the real power of causes is placed along with their connection and necessity I am sensible that of all the paradoxes which I have had or shall hereafter have occasion to advance in the course of this treatise the present one is the most violent and that it is merely by dent of solid proof and reasoning I can ever hope it will have admission and overcome the inveterate prejudices of mankind before we are reconciled to this doctrine how often must we repeat to ourselves that the simple view of any two objects or actions however related can never give us any idea of power or of a connection betwixt them that this idea arises from the repetition of their union that the repetition neither discovers nor causes anything in the objects but has an influence only on the mind by that customary transition it produces that this customary transition is therefore the same with the power and necessity which are consequently qualities of perceptions not of objects and are internally felt by the soul and not perceived externally in bodies there is commonly an astonishment attending everything extraordinary and this astonishment changes immediately into the highest degree of esteem or contempt according as we approve or disapprove of the subject I am much afraid that though the foregoing reasoning appears to me the shortest and most decisive imaginable yet with the generality of readers the bias of the mind will prevail and give them a prejudice against the present doctrine this contrary bias is easily accounted for it is a common observation that the mind has a great propensity to spread itself on external objects and to conjoin with them any internal impressions which they occasion and which always make their appearance at the same time that these objects discover themselves to the senses thus as certain sounds and smells are always found to attend certain visible objects we naturally imagine a conjunction even in place betwixt the objects and qualities though the qualities be of such a nature as to admit of no such conjunction and really exist nowhere but of this more fully hereafter in part four section five meanwhile it is sufficient to observe that the same propensity is the reason why we suppose necessity and power to lie in the objects we consider not in our mind that considers them notwithstanding it is not possible for us to form the most distant idea of that quality when it is not taken for the determination of the mind to pass from the idea of an object to that of its usual attendant but though this be the only reasonable account we can give of necessity the contrary notion is so riveted in the mind from the principles above mentioned that I doubt not but my sentiments will be treated by many as extravagant and ridiculous what the efficacy of causes lie in the determination of the mind as if causes did not operate entirely independent of the mind and would not continue their operation even though there was no mind existent to contemplate them or reason concerning them thought may well depend on causes for its operation but not causes on thought this is to reverse the order of nature and make that secondary which is really primary to every operation there is a power proportioned and this power must be placed on the body that operates if we remove the power from one cause we must ascribe it to another but to remove it from all causes and bestow it on a being that is no ways related to the cause or effect but by perceiving them is a gross absurdity and contrary to the most certain principles of human reason I can only reply to all these arguments that the case is here much the same as if a blind man should pretend to find a great many absurdities in the supposition that the color of scarlet is not the same with the sound of a trumpet nor light the same with solidity if we have really no idea of a power or efficacy in any object or of any real connection betwixt causes and effects it will be too little purpose to prove that an efficacy is necessary in all operations we do not understand our own meaning in talking so but ignorantly confound ideas which are entirely distinct from each other I am indeed ready to allow that there may be several qualities both in material and immaterial objects with which we are utterly unacquainted and if we please to call these power or efficacy it will be of little consequence to the world but when instead of meaning these unknown qualities we make the terms of power and efficacy signify something of which we have a clear idea and which is incompatible with those objects to which we apply it obscurity and error begin then to take place and we are led astray by a false philosophy this is the case when we transfer the determination of the thought to external objects and suppose any real intelligible connection betwixt them that being a quality which can only belong to the mind that considers them as to what may be said that the operations of nature are independent of our thought and reasoning I allow it and accordingly have observed that objects bear to each other the relations of contiguity and succession that like objects may be observed in several instances to have like relations and that all this is independent of and antecedent to the operations of the understanding but if we go any further and describe a power or necessary connection to these objects this is what we can never observe in them but must draw the idea of it from what we feel internally in contemplating them and this I carry so far that I am ready to convert my present reasoning into an instance of it by a subtlety which it will not be difficult to comprehend when any object is presented to us it immediately conveys to the mind a lively idea of that object which is usually found to attend it and this determination of the mind forms the necessary connection of these objects but when we change the point of view from the objects to the perceptions in that case the impression is to be considered as the cause and the lively idea as the effect and their necessary connection is that new determination which we feel to pass from the idea of the one to that of the other the uniting principle among our internal perceptions is as unintelligible as that among external objects and is not known to us any other way than by experience now the nature and effects of experience have been already sufficiently examined and explained it never gives us any insight into the internal structure or operating principle of objects but only accustoms the mind to pass from one to the other it is now time to collect all the different parts of this reasoning and by joining them together form an exact definition of the relation of cause and effect which makes the subject of the present inquiry this order would not have been excusable of first examining our inference from the relation before we had explained the relation itself had it been possible to proceed in a different method but as the nature of the relation depends so much on that of the inference we have been obliged to advance in this seemingly preposterous manner and make use of terms before we were able exactly to define them or fix their meaning we shall now correct this fault by giving a precise definition of cause and effect there may two definitions be given of this relation which are only different by their presenting a different view of the same object and making us consider it either as a philosophical or as a natural relation either as a comparison of two ideas or as an association betwixt them we may define a cause to be an object precedent and contiguous to another and where all the objects resembling the former are placed in like relations of precedency and contiguity to those objects that resemble the latter if this definition be esteemed defective because drawn from objects foreign to the cause we may substitute this other definition in its place that is a cause is an object precedent and contiguous to another and so united with it that the idea of the one determines the mind to form the idea of the other and the impression of the one to form a more lively idea of the other should this definition also be rejected for the same reason i know no other remedy than that the persons who express this delicacy should substitute adjuster definition in its place but for my part i must own my incapacity for such an undertaking when i examine with the utmost accuracy those objects which are commonly denominated causes and effects i find in considering a single instance that the one object is precedent and contiguous to the other and in enlarging my view to consider several instances i find only that like objects are constantly placed in like relations of succession and contiguity again when i consider the influence of this constant conjunction i perceive that such a relation can never be an object of reasoning and can never operate upon the mind but by means of custom which determines the imagination to make a transition from the idea of one object to that of its usual attendant and from the impression of one to a more lively idea of the other however extraordinary these sentiments may appear i think it fruitless to trouble myself with any further inquiry or reasoning upon the subject but shall repose myself on them as on established maxims it will only be proper before we leave this subject to draw some corollaries from it by which we may remove several prejudices and popular errors that have very much prevailed in philosophy first we may learn from the foregoing doctrine that all causes are of the same kind and that in particular there is no foundation for that distinction which we sometimes make betwixt efficient causes and causes sine qua non or betwixt efficient causes and formal and material and exemplary and final causes for as our idea of efficiency is derived from the constant conjunction of two objects wherever this is observed the cause is efficient and where it is not there can never be a cause of any kind for the same reason we must reject the distinction betwixt cause and occasion when supposed to signify anything essentially different from each other if constant conjunction be implied in what we call occasion it is a real cause if not it is no relation at all and cannot give rise to any argument or reasoning secondly the same course of reasoning will make us conclude that there is but one kind of necessity as there is but one kind of cause and that the common distinction betwixt moral and physical necessity is without any foundation in nature this clearly appears from the precedent explication of necessity it is the constant conjunction of objects along with the determination of the mind which constitutes a physical necessity and the removal of these is the same thing with chance as objects must either be conjoined or not and as the mind must either be determined or not to pass from one object to another it is impossible to admit of any medium betwixt chance and an absolute necessity in weakening this conjunction and determination you do not change the nature of the necessity since even in the operation of bodies these have different degrees of constancy and force without producing a different species of that relation the distinction which we often make betwixt power and the exercise of it is equally without foundation thirdly we may now be able fully to overcome all that repugnance which it is so natural for us to entertain against the foregoing reasoning by which we endeavored to prove that the necessity of a cause to every beginning of existence is not founded on any arguments either demonstrative or intuitive such an opinion will not appear strange after the foregoing definitions if we define a cause to be an object precedent and contiguous to another and where all the objects resembling the former are placed in a like relation of priority and contiguity to those objects that resemble the latter we may easily conceive that there is no absolute nor metaphysical necessity that every beginning of existence should be attended with such an object if we define a cause to be an object precedent and contiguous to another and so united with it in the imagination that the idea of the one determines the mind to form the idea of the other and the impression of the one to form a more lively idea of the other we shall make still less difficulty of ascending to this opinion such an influence on the mind is in itself perfectly extraordinary and incomprehensible nor can we be certain of its reality but from experience and observation I shall add as a fourth corollary that we can never have reason to believe that any object exists of which we cannot form an idea for as all our reasonings concerning existence are derived from causation and as all our reasonings concerning causation are derived from the experienced conjunction of objects not from any reasoning or reflection the same experience must give us a notion of these objects and must remove all mystery from our conclusions this is so evident that it would scarce have merited our attention were it not to obviate certain objections of this kind which might arise against the following reasonings concerning matter and substance I need not observe that a full knowledge of the object is not requisite but only of those qualities of it which we believe to exist end of file 29 file 30 of a treatise of human nature by David Hume volume one this LibriVox recording is in the public domain recording by George Jaeger book one part three section 15 rules by which to judge of causes and effects according to the precedent doctrine there are no objects which by the mere survey without consulting experience we can determine to be the causes of any other and no objects which we can certainly determine in the same manner not to be the causes anything may produce anything creation annihilation motion reason volition all these may arise from one another or from any other object we can imagine nor will disappear strange if we compare two principles explained above that the constant conjunction of objects determines their causation and in part one section five that properly speaking no objects are contrary to each other but existence and non-existence where objects are not contrary nothing hinders them from having that constant conjunction on which the relation of cause and effect totally depends since therefore it is possible for all objects to become causes or effects to each other it may be proper to fix some general rules by which we may know when they really are so one the cause and effect must be contiguous in space and time two the cause must be prior to the effect three there must be a constant union betwixt the cause and effect it is chiefly this quality that constitutes the relation four the same cause always produces the same effect and the same effect never arises but from the same cause this principle we derive from experience and is the source of most of our philosophical reasonings for when by any clear experiment we have discovered the causes or effects of any phenomenon we immediately extend our observation to every phenomenon of the same kind without waiting for that constant repetition from which the first idea of this relation is derived five there is another principle which hangs upon this that is that where several different objects produce the same effect it must be by means of some quality which we discover to be common amongst them for as like effects imply like causes we must always ascribe the causation to the circumstance wherein we discover the resemblance six the following principle is founded on the same reason the difference in the effects of two resembling objects must proceed from that particular in which they differ for as like causes always produce like effects when in any instance we find our expectation to be disappointed we must conclude that this irregularity proceeds from some difference in the causes seven when any object increases or diminishes with the increase or diminution of its cause it is to be regarded as a compounded effect derived from the union of the several different effects which arise from the several different parts of the cause the absence or presence of one part of the cause is here supposed to be always attended with the absence or presence of a proportionable part of the effect this constant conjunction sufficiently proves that the one part is the cause of the other we must however beware not to draw such a conclusion from a few experiments a certain degree of heat gives pleasure if you diminish that heat the pleasure diminishes but it does not follow that if you augment it beyond a certain degree the pleasure will likewise augment for we find that it degenerates into pain eight the eighth and last rule I shall take notice of is that an object which exists for any time in its full perfection without any effect is not the sole cause of that effect but requires to be assisted by some other principle which may forward its influence and operation for as like for as like effects necessarily follow from like causes and in a contiguous time and place their separation for a moment shoes that these causes are not complete once here is all the logic I think proper to employ in my reasoning and perhaps even this was not very necessary but might have been supplied by the natural principles of our understanding our scholastic headpieces and logicians shoot no such superiority above the mere vulgar in their reason and ability as to give us any inclination to imitate them in delivering a long system of rules and precepts to direct our judgment in philosophy all the rules of this nature are very easy in their invention but extremely difficult in their application and even experimental philosophy which seems the most natural and simple of any requires the utmost stretch of human judgment there is no phenomenon in nature but what is compounded and modified by so many different circumstances that in order to arrive at the decisive point we must carefully separate whatever is superfluous and inquire by new experiments if every particular circumstance of the first experiment was essential to it these new experiments are liable to a discussion of the same kind so that the utmost constancy is required to make us persevere in our inquiry and the utmost sagacity to choose the right way among so many that present themselves if this be the case even in natural philosophy how much more in moral where there is a much greater complication of circumstances and where those views and sentiments which are essential to any action of the mind are so implicit and obscure that they often escape our strictest attention and are not only unaccountable in their causes but even unknown in their existence i am much afraid less the small success i meet with in my inquiries will make this observation bear the air of an apology rather than a boasting if anything can give me security in this particular it will be the enlarging of the sphere of my experiments as much as possible for which reason it may be proper in this place to examine the reasoning faculty of brutes as well as that of human creatures and a file 30 file 31 of a treatise of human nature by david hume volume one this libra vox recording is in the public domain recording by george yeager book 1 part 3 section 16 of the reason of animals next to the ridicule of denying an evident truth is that of taking much pains to defend it and no truth appears to me more evident than that beasts are endowed with thought and reason as well as men the arguments are in this case so obvious that they never escape the most stupid and ignorant we are conscious that we ourselves in adapting means to ends are guided by reason and design and that it is not ignorantly nor casually we perform those actions which tend to self preservation to the obtaining pleasure and avoiding pain when therefore we see other creatures in millions of instances perform like actions and direct them to the ends all our principles of reason and probability carry us with an invincible force to believe the existence of a like cause it is needless in my opinion to illustrate this argument by the enumeration of particulars the smallest attention will supply us with more than our requisite the resemblance betwixt the actions of animals and those of men is so entire in this respect that the very first action of the first animal we shall please to pitch on will afford us an incontestable argument for the present doctrine this doctrine is as useful as it is obvious and furnishes us with a kind of touchstone by which we may try every system in this species of philosophy it is from the resemblance of the external actions of animals to those we ourselves perform that we judge their internal likewise to resemble ours and the same principle of reasoning carried one step further will make us conclude that since our internal actions resemble each other the causes from which they are derived must also be resembling when any hypothesis therefore is advanced to explain a mental operation which is common to men and beasts we must apply the same hypothesis to both and as every true hypothesis will abide this trial so I may venture to affirm that no false one will ever be able to endure it the common defect of those systems which philosophers have employed to account for the actions of the mind is that they suppose such a subtlety and refinement of thought as not only exceeds the capacity of mere animals but even of children and the common people in our own species who people in our own species who are not withstanding susceptible of the same emotions and affections as persons of the most accomplished genius and understanding such a subtlety is a clear proof of the falsehood as the contrary simplicity of the truth of any system let us therefore put our present system concerning the nature of the understanding to this decisive trial and see whether it will equally account for the reasonings of beasts as for these of the human species here we must make a distinction betwixt those actions of animals which are of vulgar nature and seem to be on a level with their common capacities and those more extraordinary instances of sagacity which they sometimes discover for their own preservation and the propagation of their species a dog that avoids fire and precipices that shuns strangers and caresses his master affords us an instance of the first kind a bird that chooses with such care and nicety the place and materials of her nest and sits upon her eggs for a due time and in suitable season with all the precaution that a chemist is capable of in the most delicate projection furnishes us with a lively instance of the second as to the former actions i assert they proceed from a reasoning that is not in itself different nor founded on different principles from that which appears in human nature it is necessary in the first place that there be some impression immediately present to their memory or senses in order to be the foundation of their judgment from the tone of voice the dog infers his master's anger and foresees his own punishment from a certain sensation affecting his smell he judges his game not to be far distant from him secondly the inference he draws from the present impression is built on experience and on his observation of the conjunction of objects in past instances as you vary this experience he varies his reasoning make a beating follow upon one sign or motion for some time and afterwards upon another and he will successively draw different conclusions according to his most recent experience now let any philosopher make a trial and endeavor to explain that act of the mind which we call belief and give an account of the principles from which it is derived independent of the influence of custom on the imagination and let his hypothesis be equally applicable to beasts as to the human species and after he has done this i promise to embrace his opinion but at the same time i demand as an equitable condition that if my system be the only one which can answer to all these terms it may be received as entirely satisfactory and convincing and that it is the only one is evident almost without any reasoning beasts certainly never certainly never perceive any real connection among objects it is therefore by experience they infer one from another they can never by any arguments form a general conclusion that those objects of which they have had no experience resemble those of which they have it is therefore by means of custom alone that experience operates upon them all this was sufficiently evident with respect to man but with respect to beasts there cannot be the least suspicion of mistake which must be owned to be a strong confirmation or rather an invincible proof of my system nothing shoes more the force of habit in reconciling us to any phenomenon than this that men are not astonished at the operations of their own reason at the same time that they admire the instinct of animals and find a difficulty in explaining it merely because it cannot be reduced to the very same principles to consider the matter a right reason is nothing but a wonderful and unintelligible instinct in our souls which carries us along a certain train of ideas and endows them with particular qualities according to their particular situations and relations this instinct it is true arises from past observation and experience but can anyone give the ultimate reason why past experience and observation produces such an effect anymore than why nature alone should produce it nature may certainly produce whatever can arise from habit nay habit is nothing but one of the principles of nature and derives all its force from that origin end of file 31