File Zero of a Treatise of Human Nature by David Hume, Volume 1. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. Recording by George Yeager. Contents. Advertisement. Introduction by the author. Book one of the understanding. Part one of ideas, their origin, composition, connection, abstraction, etc. Section one of the origin of our ideas. Section two, division of the subject. Section three of the ideas of the memory and imagination. Section four of the connection or association of ideas. Section five of relations. Section six of modes and substances. Section seven of abstract ideas. Part two of the ideas of space and time. Section one of the infinite divisibility of our ideas of space and time. Section two of the infinite divisibility of space and time. Section three of the other qualities of our idea of space and time. Section four, objections answered. Section five, the same subject continued. Section six of the idea of existence and of external existence. Part three of knowledge and probability. Section one of knowledge. Section two of probability and of the idea of cause and effect. Section three, why a cause is always necessary. Section four of the component parts of our reasonings concerning cause and effect. Section five of the impressions of the senses and memory. Section six of the inference from the impression to the idea. Section seven of the nature of the idea or belief. Section eight of the causes of belief. Section nine of the effects of other relations and other habits. Section 10 of the influence of belief. Section 11 of the probability of chances. Section 12 of the probability of causes. Section 13 of unphilosophical probability. Section 14 of the idea of necessary connection. Section 15 rules by which to judge of causes and effects. Section 16 of the reason of animals. Part four of the skeptical and other systems of philosophy. Section one of skepticism with regard to reason. Section two of skepticism with regard to the senses. Section three of the ancient philosophy. Section four of the modern philosophy. Section five of the immateriality of the soul. Section six of personal identity. Section seven, conclusion of this book. Volume two, book two of the passions. Part one of pride and humility. Section one, division of the subject. Section two of pride and humility, their objects and causes. Section three, whence these objects and causes are derived. Section four of the relations of impressions and ideas. Section five of the influence of these relations on pride and humility. Section six, limitations of this system. Section seven of vice and virtue. Section eight of beauty and deformity. Section nine of external advantages and disadvantages. Section 10 of property and riches. Section 11 of the love of fame. Section 12 of the pride and humility of animals. Part two of love and hatred. Section one of the object and causes of love and hatred. Section two, experiments to confirm this system. Section three, difficulties solved. Section four of the love of relations. Section five of our esteem for the rich and powerful. Section six of benevolence and anger. Section seven of compassion. Section eight of malice and envy. Section nine of the mixture of benevolence and anger with compassion and malice. Section 10 of respect and contempt. Section 11 of the amorous passion or love betwixt the sexes. Section 12 of the love and hatred of animals. Part three of the will and direct passions. Section one of liberty and necessity. Section two, the same subject continued. Section three of the influencing motives of the will. Section four of the causes of the violent passions. Section five of the effects of custom. Section six of the influence of the imagination on the passions. Section seven of contiguity and distance in space and time. Section eight, the same subject continued. Section nine of the direct passions. Section 10 of curiosity or the love of truth. Book three of morals. Part one of virtue and vice in general. Section one, moral distinctions not derived from reason. Section two, moral distinctions derived from a moral sense. Part two of justice and injustice. Section one, justice whether a natural or artificial virtue. Section two of the origin of justice and property. Section three of the rules which determine property. Section four of the transference of property by consent. Section five of the obligation of promises. Section six, some farther reflections concerning justice and injustice. Section seven of the origin of government. Section eight of the source of allegiance. Section nine of the measures of allegiance. Section 10 of the objects of allegiance. Section 11 of the laws of nations. Section 12 of chastity and modesty. Part three of the other virtues and vices. Section one of the origin of the natural virtues and vices. Section two of greatness of mind. Section three of goodness and benevolence. Section four of natural abilities. Section five, some farther reflections concerning the natural virtues. Section six, conclusion of this book. Appendix to the treatise of human nature. End of file zero. File one of a treatise of human nature by David Hume. Volume one. This LibriVox recording is in the public domain. Recording by George Yeager. Advertisement. My design in the present work is sufficiently explained in the introduction. The reader must only observe that all the subjects I have there planned out to myself are not treated of in these two volumes. The subjects of the understanding and passions make a complete chain of reasoning by themselves. And I was willing to take advantage of this natural division in order to try the taste of the public. If I have the good fortune to meet with success, I shall proceed to the examination of morals, politics, and criticism, which will complete this treatise of human nature. The approbation of the public I consider as the greatest reward of my labours, but am determined to regard its judgement, whatever it be, as my best instruction. End of file one. File two of a treatise of human nature by David Hume. Volume one. This LibriVox recording is in the public domain. Recording by George Yeager. Of the understanding. Introduction. Nothing is more usual and more natural for those who pretend to discover anything new to the world in philosophy and the sciences than to insinuate the praises of their own systems by decrying all those which have been advanced before them. And indeed were they content with lamenting that ignorance, which we still lie under in the most important questions that can come before the tribunal of human reason, there are few who have an acquaintance with the sciences that would not readily agree with them. It is easy for one of judgement and learning to perceive the weak foundation even of those systems which have obtained the greatest credit and have carried their pretensions highest to accurate and profound reasoning. Principles taken upon trust. Consequences leanly deduced from them. Want of coherence in the parts and of evidence in the whole. These are everywhere to be met with in the systems of the most eminent philosophers and seem to have drawn disgrace upon philosophy itself. Nor is there required such profound knowledge to discover the present imperfect condition of the sciences. But even the rabble without doors may judge from the noise and clamor which they hear that all goes not well within. There is nothing which is not the subject of debate and in which men of learning are not of contrary opinions. The most trivial question escapes not our controversy and in the most momentous we are not able to give any certain decision. Disputes are multiplied as if everything was uncertain and these disputes are managed with the greatest warmth as if everything was certain. Amidst all this bustle it is not reason which carries the prize but eloquence and no man needs ever despair of gaining proselytes to the most extravagant hypothesis who has art enough to represent it in any favourable colours. The victory is not gained by the men at arms who manage the pike and the sword but by the trumpeters, drummers and musicians of the army. From hence in my opinion arises that common prejudice against metaphysical reasonings of all kinds, even amongst those who profess themselves scholars and have a just value for every other part of literature. By metaphysical reasonings they do not understand those on any particular branch of science but every kind of argument which is anyway abstruse and requires some attention to be comprehended. We have so often lost our labour in such researches that we commonly reject them without hesitation and resolve if we must forever be a prey to errors and delusions that they shall at least be natural and entertaining. And indeed nothing but the most determined scepticism along with a great degree of indolence can justify this aversion to metaphysics. For if truth be at all within the reach of human capacity it is certain it must lie very deep and abstruse and to hope we shall arrive at it without pains while the greatest geniuses have failed with the utmost pains must certainly be esteemed sufficiently vain and presumptuous. I pretend to know such advantage in the philosophy I am going to unfold and would esteem it a strong presumption against it where it is so very easy and obvious. It is evident that all the sciences have a relation greater or less to human nature and that however wide any of them may seem to run from it they still return back by one passage or another. Even mathematics, natural philosophy and natural religion are in some measure dependent on the science of man since they lie under the cognizance of men and are judged of by their powers and faculties. It is impossible to tell what changes and improvements we might make in these sciences where we thoroughly acquainted with the extent and force of human understanding and could explain the nature of the ideas we employ and of the operations we perform in our reasonings. And these improvements are the more to be hoped for in natural religion as it is not content with instructing us in the nature of superior powers but carries its views farther to their disposition towards us and our duties towards them and consequently we ourselves are not only the beings that reason but also one of the objects concerning which we reason. If therefore the sciences of mathematics, natural philosophy and natural religion have such a dependence on the knowledge of men what may be expected in the other sciences whose connection with human nature is more close and intimate. The sole end of logic is to explain the principles and operations of our reasoning faculty and the nature of our ideas. Morals and criticism regard our tastes and sentiments and politics consider men as united in society and dependent on each other. In these four sciences of logic, morals, criticism and politics is comprehended almost everything which it can any way import us to be equated with or which can tend either to the improvement or ornament of the human mind. Here then is the only expedient from which we can hope for success in our philosophical researches, to leave the tedious lingering method which we have hitherto followed and instead of taking now and then a castle or village on the frontier to march up directly to the capital or center of these sciences. From this station we may extend our conquests over all those sciences which more intimately concern human life and may afterwards proceed at leisure to discover more fully those which are the objects of pure curiosity. There is no question of importance whose decision is not comprised in the science of man and there is none which can be decided with any certainty before we become acquainted with that science. In pretending therefore to explain the principles of human nature, we in effect propose a complete system of the sciences, built on a foundation almost entirely new and the only one upon which they can stand with any security. And as the science of man is the only solid foundation for the other sciences, so the only solid foundation we can give to this science itself must be laid on experience and observation. It is no astonishing reflection to consider that the application of experimental philosophy to moral subjects should come after that to natural at the distance of above a whole century. Since we find in fact that there was about the same interval betwixt the origins of these sciences and that reckoning from tallies to Socrates the space of time is nearly equal to that betwixt my lord Bacon and some late philosophers. Mr. Locke, my lord Shaftesbury, Dr. Mandeville, Mr. Hutchinson, Dr. Butler, etc., in England, who have begun to put the science of man on a new footing and have engaged the attention and excited the curiosity of the public. So true it is that however other nations may rival us in poetry and excel us in some other agreeable arts, the improvements in reason and philosophy can only be owing to a land of toleration and of liberty. Nor ought we to think that this latter improvement in the science of man will do less honor to our native country than the former in natural philosophy, but ought rather to esteem it a greater glory upon account of the greater importance of that science as well as the necessity it lay under of such a reformation. For to me it seems evident that the essence of the mind being equally unknown to us with that of external bodies, it must be equally impossible to form any notion of its powers and qualities otherwise than from careful and exact experiments and the observation of those particular effects which result from its different circumstances and situations. And though we must endeavor to render all our principles as universal as possible by tracing up our experiments to the utmost and explaining all effects from the simplest and fewest causes, it is still certain we cannot go beyond experience. And any hypothesis that pretends to discover the ultimate original qualities of human nature ought at first to be rejected as presumptuous and chimerical. I do not think a philosopher who would apply himself so earnestly to the explaining the ultimate principles of the soul would show himself a great master in that very science of human nature which he pretends to explain. Or very knowing in what is naturally satisfactory to the mind of man. For nothing is more certain than that despair has almost the same effect upon us with enjoyment. And that we are no sooner acquainted with the impossibility of satisfying any desire than the desire itself vanishes. When we see that we have arrived at the utmost extent of human reason, we sit down contented, though we be perfectly satisfied in the main of our ignorance and perceive that we can give no reason for our most general and most refined principles beside our experience of their reality, which is the reason of the mere vulgar and what it required no study at first to have discovered for the most particular and most extraordinary phenomenon. And as this impossibility of making any further progress is enough to satisfy the reader, so the writer may derive a more delicate satisfaction from the free confession of his ignorance and from his prudence in avoiding that error into which so many have fallen of imposing their conjectures and hypotheses on the world for the most certain principles. When this mutual contentment and satisfaction can be obtained betwixt the master and the scholar, I know not what more we can require of our philosophy. But if this impossibility of explaining ultimate principles should be esteemed a defect in the science of man, I will venture to affirm that it is a defect common to it with all the sciences and all the arts in which we can employ ourselves whether they be such as are cultivated in the schools of the philosophers or practiced in the shops of the meanest artisans. None of them can go beyond experience or establish any principles which are not founded on that authority. Moral philosophy has indeed this peculiar disadvantage which is not found in natural, that in collecting its experiments it cannot make them purposely with premeditation and after such a manner as to satisfy itself concerning every particular difficulty which may be. When I am at a loss to know the effects of one body upon another in any situation, I need only put them in that situation and observe what results from it. But should I endeavor to clear up after the same manner any doubt in moral philosophy by placing myself in the same case with that which I consider, it is evident this reflection and premeditation would so disturb the operation of my natural principles as must render it impossible to form any just conclusion from the phenomenon. We must therefore glean up our experiments in this science from a cautious observation of human life and take them as they appear in the common course of the world by men's behavior in company, in affairs, and in their pleasures. Where experiments of this kind are judiciously collected and compared, we may hope to establish on them a science which will not be inferior in certainty and will be much superior in utility to any other of human comprehension. End of File 2 File 3 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 of The Understanding Part 1 of Ideas, Their Origin, Composition, Connection, Abstraction, etc. Section 1 of The Origin of Our Ideas All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call Impressions and Ideas. The difference betwixt these consists in the degrees of force and liveliness with which they strike upon the mind and make their way into our thought or consciousness. Those perceptions which enter with most force and violence, we may name Impressions. And under this name, I comprehend all our sensations, passions, and emotions as they make their first appearance in the soul. By Ideas, I mean the faint images of these in thinking and reasoning, such as, for instance, are all the perceptions excited by the present discourse, accepting only those which arise from the sight and touch, and accepting the immediate pleasure or uneasiness it may occasion. I believe it will not be very necessary to employ many words in explaining this distinction. Every one of himself will readily perceive the difference betwixt feeling and thinking. The common degrees of these are easily distinguished, though it is not impossible, but in particular instances, they may very nearly approach to each other. Thus, in sleep, in a fever, in madness, or in any very violent emotions of soul, our Ideas may approach to our Impressions. As on the other hand, it sometimes happens that our Impressions are so faint and low that we cannot distinguish them from our Ideas. But notwithstanding this near resemblance in a few instances, they are in general so very different that no one can make a scruple to rank them under distinct heads and assign to each a peculiar name to mark the difference. Footnote one, I hear make use of these terms, Impression and Idea, in a sense different from what is usual, and I hope this liberty will be allowed me. Perhaps I rather restore the word Idea to its original sense, from which Mr. Locke had perverted it, in making it stand for all our perceptions. By the terms of Impression, I would not be understood to express the manner in which our lively perceptions are produced in the soul, but merely the perceptions themselves, for which there is no particular name either in the English or any other language that I know of. End of footnote one, there is another division of our perceptions which it will be convenient to observe and which extends itself both to our Impressions and Ideas. This division is into Simple and Complex. Simple perceptions or Impressions and Ideas are such as admit of no distinction nor separation. The complex are the contrary to these and may be distinguished in two parts. Though a particular color, taste and smell are qualities all united together in this apple, it is easy to perceive they are not the same, but are at least distinguishable from each other. Having by these divisions given an order and arrangement to our objects, we may now apply ourselves to consider with the more accuracy their qualities and relations. The first circumstance that strikes my eye is the great resemblance betwixt our Impressions and Ideas in every other particular, except their degree of force and vivacity. The one seem to be, in a manner, the reflection of the other, so that all the perceptions of the mind are double and appear both as Impressions and Ideas. When I shut my eyes and think of my chamber, the Ideas I form are exact representations of the Impressions I felt, nor is there any circumstance of the one which is not to be found in the other. In running over my other perceptions, I find still the same resemblance and representation. Ideas and Impressions appear always to correspond to each other. This circumstance seems to me remarkable and engages my attention for a moment. Upon a more accurate survey, I find I have been carried away too far by the first appearance, and that I must make use of the distinction of perceptions into simple and complex to limit this general decision that all our Ideas and Impressions are resembling. I observe that many of our complex Ideas never had Impressions that corresponded to them, and that many of our complex Impressions never are exactly copied in Ideas. I can imagine to myself such a city as the New Jerusalem, whose pavement is gold and walls are rubies, though I never saw any such. I have seen Paris, but shall I affirm I can form such an idea of that city as will perfectly represent all its streets and houses in their real and just proportions? I perceive, therefore, that though there is in general a great resemblance betwixt our complex Impressions and Ideas, yet the rule is not universally true that they are exact copies of each other. We may next consider how the case stands with our simple perceptions. After the most accurate examination of which I am capable, I venture to affirm that the rule here holds without any exception, and that every simple idea has a simple impression which resembles it, and every simple impression a correspondent idea. That idea of red which we form in the dark, and that impression which strikes our eyes in sunshine differ only in degree, not in nature. That the case is the same with all our simple Impressions and Ideas. It is impossible to prove by a particular enumeration of them. Everyone may satisfy himself in this point by running over as many as he pleases. But if anyone should deny this universal resemblance, I know no way of convincing him but by desiring him to shoe a simple impression that has not a correspondent idea or a simple idea that has not a correspondent impression. If he does not answer this challenge as it is certain he cannot, we may from his silence and our own observation establish our conclusion. Thus we find that all simple Ideas and Impressions resemble each other, and as the complex are formed from them, we may affirm in general that these two species of perception are exactly correspondent. Having discovered this relation, which requires no further examination, I am curious to find some other of their qualities. Let us consider how they stand with regard to their existence, and which of the Impressions and Ideas are causes and which effects. The full examination of this question is the subject of the present treatise, and therefore we shall hear content ourselves with establishing one general proposition. That all our simple Ideas in their first appearance are derived from simple Impressions which are correspondent to them and which they exactly represent. In seeking for phenomena to prove this proposition, I find only those of two kinds, but in each kind the phenomena are obvious, numerous, and conclusive. I first make myself certain by a new review of what I have already asserted, that every simple impression is attended with a correspondent idea and every simple idea with a correspondent impression. From this constant conjunction of resembling perceptions, I immediately conclude that there is a great connection betwixt our correspondent Impressions and Ideas, and that the existence of the one has a considerable influence upon that of the other. Such a constant conjunction in such an infinite number of instances can never arise from chance, but clearly proves a dependence of the Impressions on the Ideas or of the Ideas on the Impressions. That I may know on which side this dependence lies, I consider the order of their first appearance and find by constant experience that the simple Impressions always take the precedence of their correspondent Ideas, but never appear in the contrary order. To give a child an idea of scarlet or orange, of sweet or bitter, I present the objects, or in other words, convey to him these Impressions, but proceed not so absurdly as to endeavor to produce the Impressions by exciting the Ideas. Our Ideas upon their appearance produce not their correspondent Impressions, nor do we perceive any color or feel any sensation merely upon thinking of them. On the other hand, we find that any impression either of the mind or body is constantly followed by an idea which resembles it and is only different in the degrees of force and liveliness. The constant conjunction of our resembling perceptions is a convincing proof that the one are the causes of the other, and this priority of the Impressions is an equal proof that our Impressions are the causes of our Ideas, not our Ideas of our Impressions. To confirm this, I consider another plain and convincing phenomenon, which is that wherever by any accident the faculties which give rise to any Impressions are obstructed in their operations as when one is born blind or deaf, not only the Impressions are lost, but also their correspondent Ideas, so that there never appear in the mind the least traces of either of them, nor is this only true where the organs of sensation are entirely destroyed, but likewise where they have never been put in action to produce a particular Impression. We cannot form to ourselves a just idea of the taste of a pineapple without having actually tasted it. There is however one contradictory phenomenon which may prove that it is not absolutely impossible for Ideas to go before their correspondent Impressions. I believe it will readily be allowed that the several distinct Ideas of colors which enter by the eyes or those of sounds which are conveyed by the hearing are really different from each other, though at the same time resembling. Now if this be true of different colors, it must be no less so of the different shades of the same color that each of them produces a distinct idea independent of the rest. For if this should be denied, it is possible by the continual gradation of shades to run a color insensibly into what is most remote from it. And if you will not allow any of the means to be different, you cannot without absurdity deny the extremes to be the same. Suppose therefore a person to have enjoyed his sight for 30 years and to have become perfectly well acquainted with colors of all kinds, accepting one particular shade of blue, for instance, which it never has been his fortune to meet with. Let all the different shades of that color accept that single one be placed before him, descending gradually from the deepest to the lightest. It is plain that he will perceive a blank, where that shade is wanting and will be sensible, that there is greater distance in that place betwixt the contiguous colors than in any other. Now I ask whether it is possible for him from his own imagination to supply this deficiency and raise up to himself the idea of that particular shade, though it had never been conveyed to him by his senses. I believe there are few, but will be of opinion that he can. And this may serve as a proof that the simple ideas are not always derived from the correspondent impressions, though the instance is so particular and singular that it is scarce worth our observing, and does not merit that for it alone we should alter our general maxim. But besides this exception, it may not be amiss to remark on this head that the principle of the priority of impressions to ideas must be understood with another limitation. Namely, that as our ideas are images of our impressions, so we can form secondary ideas which are images of the primary as appears from this very reasoning concerning them. This is not properly speaking an exception to the rule so much as an explanation of it. Ideas produce the images of themselves in new ideas, but as the first ideas are supposed to be derived from impressions, it still remains true that all our simple ideas proceed either immediately or immediately from their correspondent impressions. This then is the first principle I establish in the science of human nature, nor ought we to despise it because of the simplicity of its appearance. For it is remarkable that the present question concerning the precedency of our impressions or ideas is the same with what has made so much noise in other terms when it has been disputed whether there be any innate ideas or whether all ideas be derived from sensation and reflection. We may observe that in order to prove the ideas of extension and color not to be innate, philosophers do nothing but shoe that they are conveyed by our senses. To prove the ideas of passion and desire not to be innate, they observe that we have a preceding experience of these emotions in ourselves. Now if we carefully examine these arguments, we shall find that they prove nothing but that ideas are preceded by other, more lively perceptions from which they are derived and which they represent. I hope this clear stating of the question will remove all disputes concerning it and will render this principle of more use in our reasonings than it seems hitherto to have been. End of File 3. File 4 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 1. Section 2. Division of the Subject. Since it appears that our simple impressions are prior to their correspondent ideas and that the exceptions are very rare, method seems to require we should examine our impressions before we consider our ideas. Impressions may be divided into two kinds, those of sensation and those of reflection. The first kind arises in the soul originally from unknown causes. The second is derived in a great measure from our ideas and that in the following order. An impression first strikes upon the senses and makes us perceive heat or cold, thirst or hunger, pleasure or pain of some kind or other. Of this impression there is a copy taken by the mind which remains after the impression ceases and this we call an idea. This idea of pleasure or pain when it returns upon the soul produces the new impressions of desire and aversion, hope and fear, which may properly be called impressions of reflection because derived from it. These again are copied by the memory and imagination and become ideas which perhaps in their turn give rise to other impressions and ideas so that the impressions of reflection are only antecedent to their correspondent ideas but posterior to those of sensation and derived from them. The examination of our sensations belongs more to anatomists and natural philosophers than to moral and therefore shall not at present be entered upon. And as the impressions of reflection, namely passions, desires and emotions which principally deserve our attention, arise mostly from ideas, it will be necessary to reverse that method which at first sight seems most natural. And in order to explain the nature and principles of the human mind, give a particular account of ideas before we proceed to impressions. For this reason I have here chosen to begin with ideas. File five of a treatise of human nature by David Hume, volume one. This LibriVox recording is in the public domain, read by George Yeager. Book one, part one, section three of the ideas of the memory and imagination. We find by experience that when any impression has been present with the mind, it again makes its appearance there as an idea. And this it may do after two different ways. Either when in its new appearance it retains a considerable degree of its first vivacity and is somewhat intermediate betwixt an impression and an idea, or when it entirely loses that vivacity and is a perfect idea. The faculty by which we repeat our impressions in the first manner is called the memory and the other the imagination. It is evident at first sight that the ideas of the memory are much more lively and strong than those of the imagination. And that the former faculty paints its objects in more distinct colors than any which are employed by the latter. When we remember any past event, the idea of it flows in upon the mind in a forcible manner. Whereas in the imagination, the perception is faint and languid and cannot without difficulty be preserved by the mind steady and uniform for any considerable time. Here then is a sensible difference betwixt one species of ideas and another. But of this more fully here after in part three, section five. There is another difference betwixt these two kinds of ideas which is no less evident, namely that though neither the ideas of the memory nor imagination, neither the lively nor faint ideas can make their appearance in the mind unless their correspondent impressions have gone before to prepare the way for them. Yet the imagination is not restrained to the same order and form with the original impressions, while the memory is in a manner tied down in that respect without any power of variation. It is evident that the memory preserves the original form in which its objects were presented. And that wherever we depart from it in recollecting anything, it proceeds from some defect or imperfection in that faculty. And historian may perhaps, for the more convenient carrying on of his narration, relate an event before another to which it was in fact posterior. But then he takes notice of this disorder if he be exact, and by that means replaces the idea in its new position. It is the same case in our recollection of those places and persons with which we were formerly acquainted. The chief exercise of the memory is not to preserve the simple ideas but their order and position. In short, this principle is supported by such a number of common and vulgar phenomena that we may spare ourselves the trouble of insisting on it any further. The same evidence follows us in our second principle of the liberty of the imagination to transpose and change its ideas. The fables we meet with in poems and romances put this entirely out of the question. Nature there is totally confounded and nothing mentioned but winged horses, fiery dragons, and monstrous giants. Nor will this liberty of the fancy appear strange when we consider that all our ideas are copied from our impressions and that there are not any two impressions which are perfectly inseparable. Not to mention that this is an evident consequence of the division of ideas into simple and complex. Wherever the imagination perceives a difference among ideas, it can easily produce a separation. End of File 5 File 6 of a Treatise of Human Nature by David Hume Volume 1 This LibriVox recording is in the public domain. Read by George Yeager Book 1 Part 1 Section 4 of the Connection or Association of Ideas As all simple ideas may be separated by the imagination and may be united again in what form it pleases, nothing would be more unaccountable than the operations of that faculty were it not guided by some universal principles which render it in some measure uniform with itself in all times and places. Were ideas entirely loose and unconnected, chance alone would join them, and it is impossible the same simple ideas should fall regularly into complex ones as they commonly do without some bond of union among them, some associating quality by which one idea naturally introduces another. This uniting principle among ideas is not to be considered as an inseparable connection, for that has been already excluded from the imagination. Nor yet are we to conclude that without it the mind cannot join two ideas, for nothing is more free than that faculty. But we are only to regard it as a gentle force which commonly prevails and is the cause why, among other things, languages so nearly correspond to each other, nature in a manner pointing out to everyone those simple ideas which are most proper to be united in a complex one. The qualities from which this association arises and by which the mind is after this manner conveyed from one idea to another are three, namely resemblance, contiguity in time or place, and cause and effect. I believe it will not be very necessary to prove that these qualities produce an association among ideas and upon the appearance of one idea naturally introduce another. It is plain that in the course of our thinking and in the constant revolution of our ideas, our imagination runs easily from one idea to any other that resembles it and that this quality alone is to the fancy a sufficient bond and association. It is likewise evident that as the senses in changing their objects are necessitated to change them regularly and take them as they lie contiguous to each other, the imagination must by long custom acquire the same method of thinking and run along the parts of space and time in conceiving its objects. As to the connection that is made by the relation of cause and effect, we shall have occasion afterwards to examine it to the bottom and therefore shall not at present insist upon it. It is sufficient to observe that there is no relation which produces a stronger connection in the fancy and makes one idea more readily recall another than the relation of cause and effect betwixt their objects. That we may understand the full extent of these relations, we must consider that two objects are connected together in the imagination, not only when the one is immediately resembling contiguous to or the cause of the other, but also when there is interposed betwixt them a third object which bears to both of them any of these relations. This may be carried on to a great length, though at the same time we may observe that each remove considerably weakens the relation. Cousins in the fourth degree are connected by causation, if I may be allowed to use that term, but not so closely as brothers, much less as child and parent. In general, we may observe that all the relations of blood depend upon cause and effect and are esteemed near or remote according to the number of connecting causes interposed betwixt the persons. Of the three relations above mentioned, this of causation is the most extensive. Two objects may be considered as placed in this relation as well, when one is the cause of any of the actions or motions of the other, as when the former is the cause of the existence of the latter. For as that action or motion is nothing but the object itself considered in a certain light, and as the object continues the same in all its different situations, it is easy to imagine how such an influence of objects upon one another may connect them in the imagination. We may carry this further and remark not only that two objects are connected by the relation of cause and effect when the one produces a motion or any action in the other, but also when it has a power of producing it. And this we may observe to be the source of all the relations of interest and duty by which men influence each other in society and are placed in the ties of government and subordination. A master is such a one as by his situation arising either from force or agreement as a power of directing in certain particulars the actions of another whom we call servant. A judge is one who in all disputed cases can fix by his opinion the possession or property of anything betwixt any members of the society. When a person is possessed of any power there is no more required to convert it into action but the exertion of the will, and that in every case is considered as possible and in many as probable, especially in the case of authority where the obedience of the subject is a pleasure and advantage to the superior. These are therefore the principles of union or cohesion among our simple ideas and in the imagination supply the place of that inseparable connection by which they are united in our memory. Here is a kind of attraction which in the mental world will be found to have as extraordinary effects as in the natural and to shoe itself in as many and as various forms. Its effects are everywhere conspicuous but as to its causes they are mostly unknown and must be resolved into original qualities of human nature which I pretend not to explain. Nothing is more requisite for a true philosopher than to restrain the intemperate desire of searching into causes and having established any doctrine upon a sufficient number of experiments. Rest contented with that when he sees a further examination would lead him into obscure and uncertain speculations. In that case his inquiry would be much better employed in examining the effects than the causes of his principle. Amongst the effects of this union or association of ideas there are none more remarkable than those complex ideas which are the common subjects of our thoughts and reasoning and generally arise from some principle of union among our simple ideas. These complex ideas may be divided into relations, modes and substances. We shall briefly examine each of these in order and shall subjoin some considerations concerning our general and particular ideas before we leave the present subject which may be considered as the elements of this philosophy. End of File 6 File 7 of a Treatise of Human Nature by David Hume Volume 1 This LibriVox recording is in the public domain. Read by George Yeager Book 1 Part 1 Section 5 Of Relations The relation is commonly used in two senses considerably different from each other. Either for that quality by which two ideas are connected together in the imagination, and the one naturally introduces the other after the manner above explained, or for that particular circumstance in which even upon the arbitrary union of two ideas in the fancy we may think proper to compare them. In common language the former is always the sense in which we use the word relation. And it is only in philosophy that we extend it to mean any particular subject of comparison without a connecting principle. Thus distance will be allowed by philosophers to be a true relation because we acquire an idea of it by the comparing of objects. But in a common way we say that nothing can be more distant than such or such things from each other. Nothing can have less relation as if distance and relation were incompatible. It may perhaps be esteemed an endless task to enumerate all those qualities which make objects admit of comparison and by which the ideas of philosophical relation are produced. But if we diligently consider them we shall find that without difficulty they may be comprised under seven general heads which may be considered as the sources of all philosophical relation. One, the first is resemblance and this is a relation without which no philosophical relation can exist since no objects will admit of comparison but what have some degree of resemblance. But though resemblance be necessary to all philosophical relation it does not follow that it always produces a connection or association of ideas. When a quality becomes very general and is common to a great many individuals it leads not the mind directly to any one of them but by presenting at once too great a choice does thereby prevent the imagination from fixing on any single object. Two, identity may be esteemed a second species of relation. This relation I here consider as applied in its strictest sense to constant and unchangeable objects without examining the nature and foundation of personal identity which shall find its place afterwards. Of all relations the most universal is that of identity being common to every being whose existence has any duration. Three, after identity the most universal and comprehensive relations are those of space and time which are the sources of an infinite number of comparisons such as distant, contiguous, above, below, before, after. Etc. Four, all those objects which admit of quantity or number may be compared in that particular which is another very fertile source of relation. Five, when any two objects possess the same quality in common the degrees in which they possess it form a fifth species of relation. Thus of two objects which are both heavy the one may be either of greater or less weight than the other. Two colors that are of the same kind may yet be of different shades and in that respect admit of comparison. Six, the relation of contrarity may at first sight be regarded as an exception to the rule that no relation of any kind can subsist. Without some degree of resemblance. But let us consider that no two ideas are in themselves contrary except those of existence and nonexistence which are plainly resembling as implying both of them an idea of the object. Though the latter excludes the object from all times and places in which it is supposed not to exist. Seven, all other objects such as fire and water, heat and cold are only found to be contrary from experience and from the contrarity of their causes or effects which relation of cause and effect is a seventh philosophical relation as well as a natural one. The resemblance implied in this relation shall be explained afterwards. It might naturally be expected that I should join difference to the other relations. But that I consider rather as a negation of relation than as anything real or positive. Difference is of two kinds as opposed either to identity or resemblance. The first is called a difference of number, the other of kind. And of file seven. File eight of a treatise of human nature by David Hume. Volume one. This LibriVox recording is in the public domain. Read by George Yeager. Volume one. Book one. Part one. Section six of modes and substances. I would feign ask those philosophers who found so much of their reasonings on the distinction of substance and accident. And imagine we have clear ideas of each, whether the idea of substance be derived from the impressions of sensation or of reflection. If it be conveyed to us by our senses, I ask which of them and after what manner. If it be perceived by the eyes, it must be a color. If by the ears, a sound. If by the palate, a taste. And so of the other senses. But I believe none will assert that substance is either a color or sound or a taste. The idea of substance must therefore be derived from an impression or reflection, if it really exists. But the impressions of reflection resolve themselves into our passions and emotions, none of which can possibly represent a substance. We have therefore no idea of substance distinct from that of a collection of particular qualities, nor have we any other meaning when we either talk of or reason concerning it. The idea of a substance, as well as that of a mode, is nothing but a collection of simple ideas that are united by the imagination and have a particular name assigned them by which we are able to recall either to ourselves or others that collection. But the difference betwixt these ideas consists in this, that the particular qualities which form a substance are commonly referred to an unknown something in which they are supposed to in here, or granting this fiction should not take place, are at least supposed to be closely and inseparably connected by the relations of contiguity and causation. The effect of this is that whatever new simple quality we discover to have the same connection with the rest, we immediately comprehend it among them, even though it did not enter into the first conception of the substance. Thus our idea of gold may at first be a yellow color, weight, malleable-ness, fusibility, but upon the discovery of its desolubility in aqua regia, we join that to the other qualities and suppose it to belong to the substance as much as if its idea had from the beginning made a part of the compound one. The principle of union being regarded as the chief part of the complex idea gives entrance to whatever quality afterwards occurs and is equally comprehended by it as are the others which first presented themselves. That this cannot take place in modes is evident from considering their nature. The simple ideas of which modes are formed either represent qualities which are not united by contiguity and causation but are dispersed in different subjects or if they be all united together the uniting principle is not regarded as the foundation of the complex idea. The idea of a dance is an instance of the first kind of modes, that of beauty of the second. The reason is obvious why such complex ideas cannot receive any new idea without changing the name which distinguishes the mode and of file eight, file nine of a treatise of human nature by David Hume, volume one. This LibriVox recording is in the public domain, read by George Yeager, book one, part one, section seven of abstract ideas. A very material question has been started concerning abstract or general ideas whether they be general or particular in the mind's conception of them. A great philosopher, Dr. Berkeley, has disputed the received opinion in this particular and has asserted that all general ideas are nothing but particular ones annexed to a certain term which gives them a more extensive signification and makes them recall upon occasion other individuals which are similar to them. As I look upon this to be one of the greatest and most valuable discoveries that has been made of late years in the Republic of Letters I shall here endeavor to confirm it by some arguments which I hope will put it beyond all doubt and controversy. It is evident that in forming most of our general ideas, if not all of them, we abstract from every particular degree of quantity and quality and that an object ceases not to be of any particular species on account of every small alteration in its extension, duration and other properties. It may therefore be thought that here is a plain dilemma that decides concerning the nature of those abstract ideas which have afforded so much speculation to philosophers. The abstract idea of a man represents men of all sizes and all qualities which it is concluded it cannot do but either by representing it once all possible sizes and all possible qualities or by representing no particular one at all. Now it having been esteemed absurd to defend the former proposition as implying an infinite capacity in the mind, it has been commonly inferred in favor of the latter and our abstract ideas have been supposed to represent no particular degree either of quantity or quality. But that this inference is erroneous I shall endeavor to make appear, first by proving that it is utterly impossible to conceive any quantity or quality without forming a precise notion of its degrees and secondly by showing that though the capacity of the mind be not infinite yet we can at once form a notion of all possible degrees of quantity and quality in such a manner at least as however imperfect may serve all the purposes of reflection and conversation. To begin with the first proposition that the mind cannot form any notion of quantity or quality without forming a precise notion of degrees of each. We may prove this by the three following arguments. First, we have observed that whatever objects are different are distinguishable and that whatever objects are distinguishable are separable by the thought and imagination. And we may here add that these propositions are equally true in the inverse and that whatever objects are separable are also distinguishable and that whatever objects are distinguishable are also different. For how is it possible we can separate what is not distinguishable or distinguish what is not different? In order therefore to know whether abstraction implies a separation we need only consider it in this view and examine whether all the circumstances which we abstract from in our general ideas be such as are distinguishable and different from those which we retain as essential parts of them. But it is evident at first sight that the precise length of a line is not different nor distinguishable from the line itself nor the precise degree of any quality from the quality. These ideas therefore admit no more of separation than they do of distinction and difference. They are consequently conjoined with each other in the conception and the general idea of a line notwithstanding all our abstractions and refinements has in its appearance in the mind a precise degree of quantity and quality however it may be made to represent others which have different degrees of both. Secondly, it is confessed that no object can appear to the senses or in other words that no impression can become present to the mind without being determined in its degrees both of quantity and quality. The confusion in which impressions are sometimes involved proceeds only from their faintness and unsteadiness not from any capacity in the mind to receive any impression which in its real existence has no particular degree nor proportion. That is a contradiction in terms and even implies the flattest of all contradictions namely that it is possible for the same thing both to be and not to be. Now since all ideas are derived from impressions and are nothing but copies and representations of them whatever is true of the one must be acknowledged concerning the other. Impressions and ideas differ only in their strength and vivacity. The foregoing conclusion is not founded on any particular degree of vivacity it cannot therefore be affected by any variation in that particular. An idea is a weaker impression and as a strong impression must necessarily have a determinant quantity and quality the case must be the same with its copy or representative. Thirdly, it is a principle generally received in philosophy that everything in nature is individual and that it is utterly absurd to suppose a triangle really existent which has no precise proportion of sides and angles. If this therefore be absurd in fact and reality it must also be absurd in idea since nothing of which we can form a clear and distinct idea is absurd and impossible. But to form the idea of an object and to form an idea simply is the same thing the reference of the idea to an object being an extraneous denomination of which in itself it bears no mark or character. Now as it is impossible to form an idea of an object that is possessed of quantity and quality and yet is possessed of no precise degree of either, it follows that there is an equal impossibility of forming an idea that is not limited and confined in both these particulars. Abstract ideas are therefore in themselves individual however they may become general in their representation. The image in the mind is only that of a particular object though the application of it in our reasoning be the same as if it were universal. This application of ideas beyond their nature proceeds from our collecting all their possible degrees of quantity and quality in such an imperfect manner as may serve the purposes of life which is the second proposition I propose to explain. When we have found a resemblance, footnote 2, it is evident that even different simple ideas may have a similarity or resemblance to each other, nor is it necessary that the point or circumstance of resemblance should be distinct or separable from that in which they differ. Blue and green are different simple ideas but are more resembling than blue and scarlet though their perfect simplicity excludes all possibility of separation or distinction. It is the same case with particular sounds and tastes and smells. These admit of infinite resemblances upon the general appearance and comparison without having any common circumstance the same. And of this we may be certain even from the very abstract terms simple idea. They comprehend all simple ideas under them. These resemble each other in their simplicity and yet from their very nature which excludes all composition this circumstance in which they resemble is not distinguishable nor separable from the rest. It is the same case with all the degrees in any quality. They are all resembling and yet the quality in any individual is not distinct from the degree. And of footnote 2, when we have found a resemblance among several objects that often occur to us, we apply the same name to all of them. Whatever differences we may observe in the degrees of their quantity and quality and whatever other differences may appear among them. After we have acquired a custom of this kind, the hearing of that name revives the idea of one of these objects and makes the imagination conceive it with all its particular circumstances and proportions. But as the same word is supposed to have been frequently applied to other individuals that are different in many respects from that idea which is immediately present to the mind, the word not being able to revive the idea of all these individuals but only touches the soul if I may be allowed so to speak and revives that custom which we have acquired by surveying them. They are not really and in fact present to the mind but only in power. Nor do we draw them all out distinctly in the imagination but keep ourselves in a readiness to survey any of them as we may be prompted by a present design or necessity. The word raises up an individual idea along with a certain custom and that custom produces any other individual one for which we may have occasion. But as the production of all the ideas to which the name may be applied is in most cases impossible, we abridge that work by a more partial consideration and find but few inconveniences to arise in our reasoning from that abridgement. For this is one of the most extraordinary circumstances in the present affair, that after the mind has produced an individual idea upon which we reason, the attendant custom revived by the general or abstract term readily suggests any other individual if by chance we form any reasoning that agrees not with it. Thus should we mention the word triangle and form the idea of a particular equilateral one to correspond to it, and should we afterwards assert that the three angles of a triangle are equal to each other, the other individuals of a scale num and isosceles, which we overlooked at first, immediately crowd in upon us and make us perceive the falsehood of this proposition, though it be true with relation to that idea which we had formed. If the mind suggests not always these ideas upon occasion, it proceeds from some imperfection in its faculties and such a one as is often the source of false reasoning and sophistry. But this is principally the case with those ideas which are abstruse and compounded. On other occasions the custom is more entire and it is seldom we run into such errors. Neso entire is the custom that the very same idea may be annexed to several different words and may be employed in different reasonings without any danger of mistake. Thus the idea of an equilateral triangle of an inch perpendicular may serve us in talking of a figure, of a rectilinear figure, of a regular figure, of a triangle, and of an equilateral triangle. All these terms, therefore, are in this case attended with the same idea. But as they are want to be applied in a greater or lesser compass, they excite their particular habits and thereby keep the mind in a readiness to observe that no conclusion be formed contrary to any ideas which are usually comprised under them. Before those habits have become entirely perfect, perhaps the mind may not be content with forming the idea of only one individual, but may run over several in order to make itself comprehend its own meaning and the compass of that collection which it intends to express by the general term. That we may fix the meaning of the word figure, we may revolve in our mind the ideas of circles, squares, parallelograms, triangles of different sizes and proportions and may not rest on one image or idea. However this may be, it is certain that we form the idea of individuals whenever we use any general term, that we seldom or never can exhaust these individuals, and that those which remain are only represented by means of that habit by which we recall them whenever any present occasion requires it. This then is the nature of our abstract ideas and general terms, and it is after this manner we account for the foregoing paradox that some ideas are particular in their nature, but general in their representation. A particular idea becomes general by being annexed to a general term, that is to a term which from a customary conjunction has a relation to many other particular ideas and readily recalls them in the imagination. The only difficulty that can remain on this subject must be with regard to that custom which so readily recalls every particular idea for which we may have occasion and is excited by any word or sound to which we commonly annex it. The most proper method, in my opinion, of giving a satisfactory explication of this act of the mind is by producing other instances which are analogous to it and other principles which facilitate its operation. To explain the ultimate causes of our mental actions is impossible. It is sufficient if we can give any satisfactory account of them from experience and analogy. First then I observe that when we mention any great number such as a thousand, the mind has generally no adequate idea of it, but only a power of producing such an idea by its adequate idea of the decimals under which the number is comprehended. This imperfection, however, in our ideas is never felt in our reasonings which seems to be an instance parallel to the present one of universal ideas. Secondly, we have several instances of habits which may be revived by one single word, as when a person who has by rote any periods of discourse or any number of verses will be put in remembrance of the whole, which he is that had lost to recollect by that single word or expression with which they begin. Thirdly, I believe everyone who examines the situation of his mind in reasoning will agree with me that we do not annex distinct and complete ideas to every term we make use of, and that in talking of government, church, negotiation, conquest, we seldom spread out in our minds all the simple ideas of which these complex ones are composed. It is, however, observable that notwithstanding this imperfection, we may avoid talking nonsense on these subjects and may perceive any repugnance among the ideas as well as if we had a full comprehension of them. Thus, if instead of saying that in war the weaker have always recourse to negotiation, we should say that they have always recourse to conquest, the custom which we have acquired of attributing certain relations to ideas still follows the words and makes us immediately perceive the absurdity of that proposition. In the same manner as one particular idea may serve us in reasoning concerning other ideas, however different from it in several circumstances. Fourthly, as the individuals are collected together and placed under a general term with a view to that resemblance which they bear to each other, this relation must facilitate their entrance in the imagination and make them be suggested more readily upon occasion. And indeed, if we consider the common progress of the thought either in reflection or conversation, we shall find great reason to be satisfied in this particular. Nothing is more admirable than the readiness with which the imagination suggests its ideas and presents them at the very instant in which they become necessary or useful. The fancy runs from one end of the universe to the other in collecting those ideas which belong to any subject. One would think the whole intellectual world of ideas was at once subjected to our view and that we did nothing but pick out such as were most proper for our purpose. There may not, however, be any present beside those very ideas that are thus collected by a kind of magical faculty in the soul, which, though it be always most perfect in the greatest geniuses and is properly what we call a genius, is, however, inexplicable by the utmost efforts of human understanding. Perhaps these four reflections may help to remove any difficulties to the hypothesis I have proposed concerning abstract ideas so contrary to that which has hitherto prevailed in philosophy. But to tell the truth, I place my chief confidence in what I have already proved concerning the impossibility of general ideas according to the common method of explaining them. We must certainly seek some new system on this head, and there plainly is none beside what I have proposed. If ideas be particular in their nature and at the same time finite in their number, it is only by custom they can become general in their representation and contain an infinite number of other ideas under them. Before I leave this subject, I shall employ the same principles to explain that distinction of reason which is so much talked of and is so little understood in the schools. Of this kind is the distinction betwixt figure and the body figured, motion and the body moved. The difficulty of explaining this distinction arises from the principle above explained, that all ideas which are different are separable, for it follows from thence that if the figure be different from the body, their ideas must be separable as well as distinguishable. If they be not different, their ideas can neither be separable nor distinguishable. What then is meant by a distinction of reason, since it implies neither a difference nor separation? To remove this difficulty, we must have recourse to the foregoing explication of abstract ideas. It is certain that the mind would never have dreamed of distinguishing a figure from the body figured as being in reality neither distinguishable nor different nor separable. Did it not observe that even in this simplicity there might be contained many different resemblances and relations? Thus, when a globe of white marble is presented, we receive only the impression of a white color disposed in a certain form, nor are we able to separate and distinguish the color from the form. But observing afterwards a globe of black marble and a cube of white and comparing them with our former object, we find two separate resemblances in what formerly seemed and really is perfectly inseparable. After a little more practice of this kind, we begin to distinguish the figure from the color by a distinction of reason. That is, we consider the figure and color together since they are in effect the same and undistinguishable, but still view them in different aspects according to the resemblances of which they are susceptible. When we would consider only the figure of the globe of white marble, we form in reality an idea both of the figure and color, but tacitly carry our eye to its resemblance with the globe of black marble, and in the same manner, when we would consider its color only, we turn our view to its resemblance with the cube of white marble. By this means, we accompany our ideas with a kind of reflection of which custom renders us in a great measure insensible. A person who desires us to consider the figure of a globe of white marble without thinking on its color desires an impossibility, but his meaning is that we should consider the figure and color together, but still keep in our eye the resemblance to the globe of black marble or that to any other globe of whatever color or substance. End of File 9 File 10 of a Treatise of Human Nature by David Hume Volume 1 This LibriVox recording is in the public domain. Read by George Yeager Book 1 Part 2 Of the Ideas of Space and Time Section 1 Of the Infinite Divisibility of Our Ideas of Space and Time Whatever has the air of a paradox, and is contrary to the first and most unprejudiced notions of mankind, is often greedily embraced by philosophers as shewing the superiority of their science which could discover opinions so remote from vulgar conception. On the other hand, anything proposed to us which causes surprise and admiration gives such a satisfaction to the mind that it indulges itself in those agreeable emotions and will never be persuaded that its pleasure is entirely without foundation. From these dispositions in philosophers and their disciples arises that mutual complacence betwixt them. While the former furnish such plenty of strange and unaccountable opinions, and the latter so readily believe them, of this mutual complacence I cannot give a more evident instance than in the doctrine of Infinite Divisibility with the examination of which I shall begin this subject of the Ideas of Space and Time. It is universally allowed that the capacity of the mind is limited and can never attain a full and adequate conception of infinity. And though it were not allowed, it would be sufficiently evident from the plainest observation and experience. It is also obvious that whatever is capable of being divided in infinitum must consist of an infinite number of parts, and that it is impossible to set any bounds to the number of parts without setting bounds at the same time to the division. It requires scarce any induction to conclude from hence that the idea which we form of any finite quality is not infinitely divisible, but that by proper distinctions and separations we may run up this idea to inferior ones which will be perfectly simple and indivisible. In rejecting the infinite capacity of the mind, we suppose it may arrive at an end in the division of its ideas, nor are there any possible means of evading the evidence of this conclusion. It is therefore certain that the imagination reaches a minimum and may raise up to itself an idea of which it cannot conceive any subdivision and which cannot be diminished without a total annihilation. When you tell me of the thousandth and ten thousandth part of a grain of sand, I have a distinct idea of these numbers and of their different proportions. But the images which I form in my mind to represent the things themselves are nothing different from each other, nor inferior to that image by which I represent the grain of sand itself which is supposed so vastly to exceed them. What consists of parts is distinguishable into them, and what is distinguishable is separable. But whatever we may imagine of the thing, the idea of a grain of sand is not distinguishable, nor separable into twenty, much less into a thousand, ten thousand, or an infinite number of different ideas. It is the same case with the impressions of the senses as with the ideas of the imagination.  It is plain that the moment before it vanished, the image or impression was perfectly indivisible. It is not for want of rays of light striking on our eyes that the minute parts of distant bodies convey not any sensible impression. But because they are removed beyond that distance at which their impressions were reduced to a minimum and were incapable of any further demunation. A microscope or telescope which renders them visible produces not any new rays of light, but only spreads those which always flowed from them. And by that means both gives parts to impressions which to the naked eye appear simple and uncompounded and advances to a minimum what was formerly imperceptible. We may hence discover the error of the common opinion that the capacity of the mind is limited on both sides and that it is impossible for the imagination to form an adequate idea of what goes beyond a certain degree of minuteness as well as of greatness. Nothing can be more minute than some ideas which we form in the fancy and images which appear to the senses since there are ideas and images perfectly simple and indivisible. The only defect of our senses is that they give us disproportioned images of things and represent as minute and uncompounded what is really great and composed of a vast number of parts. This mistake we are not sensible of, but taking the impressions of those minute objects which appear to the senses to be equal or nearly equal to the objects and finding by reason that there are other objects vastly more minute. We too hastily conclude that these are inferior to any idea of our imagination or impression of our senses. This however is certain that we can form ideas which shall be no greater than the smallest atom of the animal spirits of an insect a thousand times less than a mite. And we ought rather to conclude that the difficulty lies in enlarging our conception so much as to form a just notion of a mite or even of an insect a thousand times less than a mite. For in order to form a just notion of these animals we must have a distinct idea representing every part of them which according to the system of infinite divisibility is utterly impossible. And according to that of indivisible parts or atoms is extremely difficult by reason of the vast number and multiplicity of these parts. End of File 10. File 11 of a Treatise of Human Nature by David Hume. Volume 1. This LibriVox recording is in the public domain. It is read by George Yeager. Book 1. Part 2. Section 2. Of the Infinite Divisibility of Space and Time. Wherever ideas are adequate representations of objects, the relations, contradictions, and agreements of the ideas are all applicable to the objects. And this we may in general observe to be the foundation of all human knowledge. But our ideas are adequate representations of the most minute parts of extension. And through whatever divisions and subdivisions we may suppose these parts to be arrived at, they can never become inferior to some ideas which we form. The plain consequence is that whatever appears impossible and contradictory upon the comparison of these ideas must be really impossible and contradictory without any further excuse or evasion. Everything capable of being infinitely divided contains an infinite number of parts. Otherwise, the division would be stopped short by the indivisible parts which we should immediately arrive at. If, therefore, any finite extension be infinitely divisible, it can be no contradiction to suppose that a finite extension contains an infinite number of parts. And vice versa, if it be a contradiction to suppose that a finite extension contains an infinite number of parts, no finite extension can be infinitely divisible. But that this latter supposition is absurd, I easily convince myself by the consideration of my clear ideas. I first take the least idea I can form of a part of extension. And being certain that there is nothing more minute than this idea, I conclude that whatever I discover by its means must be a real quality of extension. I then repeat this idea once, twice, thrice, etc. And find the compound idea of extension arising from its repetition always to augment and become double, triple, quadruple, etc. Till at last it swells up to a considerable bulk, greater or smaller, in proportion as I repeat more or less the same idea. When I stop in the addition of parts, the idea of extension ceases to augment. And were I to carry on the addition in infinitum, I clearly perceive that the idea of extension must also become infinite. Upon the whole, I conclude that the idea of an infinite number of parts is individually the same idea with that of an infinite extension. That no finite extension is capable of containing an infinite number of parts. And consequently, that no finite extension is infinitely divisible. Footnote 3 It has been objected to me that infinite divisibility supposes only an infinite number of proportional, not of aliquot parts, and that an infinite number of proportional parts does not form an infinite extension. But this distinction is entirely frivolous. Whether these parts be called aliquot or proportional, they cannot be inferior to those minute parts we conceive, and therefore cannot form a less extension by their conjunction. End of footnote 3 I may subjoin another argument proposed by a noted author, M. Meliziu, which seems to me very strong and beautiful. It is evident that existence in itself belongs only to unity and is never applicable to number, but on account of the units of which the number is composed. Twenty men may be said to exist, but it is only because one, two, three, four, etc., are existent. And if you deny the existence of the latter, that of the former falls, of course. It is therefore utterly absurd to suppose any number to exist and yet deny the existence of units. And as extension is always a number according to the common sentiment of metaphysicians, and never resolves itself into any unit or indivisible quantity, it follows that extension can never at all exist. It is in vain to reply that any determinant quantity of extension is an unit, but such a one as admits of an infinite number of fractions and is inexhaustible in its subdivisions. For by the same rule these twenty men may be considered as a unit, the whole globe of the earth, nay the whole universe, may be considered as a unit. That term of unity is merely a fictitious denomination which the mind may apply to any quantity of objects it collects together, nor can such a unity any more exist alone than number can, as being in reality a true number. But the unity which can exist alone and whose existence is necessary to that of all number is of another kind and must be perfectly indivisible and incapable of being resolved into any lesser unity. All this reasoning takes place with regard to time, along with an additional argument which it may be proper to take notice of. It is a property inseparable from time and which in a manner constitutes its essence that each of its parts succeeds another and that none of them, however contiguous, can ever be co-existent. For the same reason that the year 1737 cannot concur with the present year 1738 every moment must be distinct from and posterior or antecedent to another. It is certain then that time as it exists must be composed of indivisible moments. For if in time we could never arrive at an end of division and if each moment as it succeeds another were not perfectly single and indivisible there would be an infinite number of co-existent moments or parts of time which I believe will be allowed to be an errant contradiction. The infinite divisibility of space implies that of time as is evident from the nature of motion. If the latter therefore be impossible, the former must be equally so. I doubt not, but it will readily be allowed by the most obstinate defender of the doctrine of infinite divisibility that these arguments are difficulties and that it is impossible to give any answer to them which will be perfectly clear and satisfactory. But here we may observe that nothing can be more observed than this custom of calling a difficulty what pretends to be a demonstration and endeavoring by that means to elude its force and evidence. It is not in demonstrations as in probabilities that difficulties can take place and one argument counterbalance another and diminish its authority. A demonstration if just admits of no opposite difficulty and if not just it is a mere sophism and consequently can never be a difficulty. It is either irresistible or has no manner of force. To talk therefore of objections and replies and balancing of arguments in such a question as this is to confess either that human reason is nothing but a play of words or that the person himself who talks so has not a capacity equal to such subjects. Demonstrations may be difficult to be comprehended because of abstractedness of the subject but can never have such difficulties as will weaken their authority when once they are comprehended. It is true, mathematicians are wont to say that there are here equally strong arguments on the other side of the question and that the doctrine of indivisible points is also liable to unanswerable objections. Before I examine these arguments and objections in detail I will here take them in a body and endeavor by a short and decisive reason to prove at once that it is utterly impossible they can have any just foundation. It is an established maxim in metaphysics that whatever the mind clearly conceives includes the idea of possible existence or in other words that nothing we imagine is absolutely impossible. We can form the idea of a golden mountain and from thence conclude that such a mountain may actually exist. We can form no idea of a mountain without a valley and therefore regard it as impossible. Now it is certain we have an idea of extension for otherwise why do we talk and reason concerning it. It is likewise certain that this idea as conceived by the imagination though divisible into parts or inferior ideas is not infinitely divisible nor consists of an infinite number of parts for that exceeds the comprehension of our limited capacities. Here then is an idea of extension which consists of parts or inferior ideas that are perfectly indivisible. Consequently this idea implies no contradiction. Consequently it is possible for extension really to exist conformable to it and consequently all the arguments employed against the possibility of mathematical points are mere scholastic quibbles and unworthy of our attention. These consequences we may carry one step further and conclude that all the pretended demonstrations for the infinite divisibility of extension are equally sophisticated. Since it is certain these demonstrations cannot be just without proving the impossibility of mathematical points which it is an evident absurdity to pretend to. End of file.