Hume's Theory of Impressions, Ideas, and Cause and Effect - Prof. George J. Mattey, Study notes of Introduction to Philosophy

Download Hume's Theory of Impressions, Ideas, and Cause and Effect - Prof. George J. Mattey and more Study notes Introduction to Philosophy in PDF only on Docsity! Instructor's Notes: Hume Treatise "fell dead-born from the press." Reviewed by Hume himself in the "Abstract." Three books: understanding, passions, morals (published later). Introduction Begins with skeptical topic. The inadequacy of current systems, the disputes that rage on, with victory to the eloquent with their extravagant hypotheses. This creates a prejudice against metaphysical reasoning, which is understood to be anything that is abstruse and that requires attention to be understood. Yet the truth is deep and requires abstruse reasoning to recover it. So we can't take the easy and obvious route. All sciences are traced to human nature, even mathematics, natural philosophy, natural religion. They are judged by human faculties, which we need to be able to assess them. More so regarding logic, morals, criticism (aesthetics), and politics. Military analogy: forget the outposts and march right up to the capital, human nature itself. The science of man is the only one which promises any security in the others. The foundation for the science of man is "experience and observation." Even though it comes after application to natural philosophy, the experimental method has come after 100 years to moral philosophy. Bacon is cited. Interesting aside: "the improvements in reason and philosophy can only be owing to a land of toleration and liberty." Now the reason for the adoption of the experimental method: the essence of the mind is as unknown as that of external bodies. We must reject hypotheses (Newton). We should be satisfied with our ignorance once we realize it is unavoidable. We cannot explain ultimate principles (another Newtonian reference). All other sciences share this defect. What should be observed is the ordinary affairs of life. It is here that "experiments" are to be "collected and compared." From Part I 1.1.1 Impressions are distinguished from ideas in terms of force and liveliness. Impressions include: sensations passions emotions Then a second criterion is given: they are original. Ideas are faint copies of the originals. There are a few instances when the two approach each other, but "they are in general so very different that no on can make a scruple to rank them under distinct heads and assign a peculiar name to mark the difference. A second division: simple and complex ideas. Simple ideas "admit of no distinction or separation." Complex ideas have parts, e.g. apple, with "a particular color, tastes and smell." We perceive that they are not the same (Locke). Ideas resemble impressions in all but vivacity. "Ideas and impressions appear always to correspond to each other." This is now qualified, in that many complex ideas do not resemble an original (New Jerusalem, recollection of Paris). However, the resemblance is perfect with simple ideas. This cannot be shown by enumeration, but Hume challenges the reader to produce a counter-example. Regarding existence and cause and effect, the impressions are the cause of the ideas. "The full examination of this question is the subject of the present treatise." We observe a constant conjunction, and "immediately conclude that there is a great connection between 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." To tell which is cause and which effect, we note that impressions come first. Priority decides which is cause and which effect. A supporting consideration is that one born without the use of a sense never has the corresponding ideas. The missing shade of blue is "so particular and singular that it is scarcely worth our observing and does not merit that we should alter our general maxim for it alone." Another apparent exception is that we can form ideas from ideas. But this is rather an explanation of the rule. The impression is the first link of a chain. To prove that there are no innate ideas, philosophers appeal to impressions. 1.1.2 Division of the Subject Impressions are divided into those of sensation and reflection. Impressions of sensation arise from unknown causes, which should be treated by anatomists and natural philosophers. Impressions of reflection arise from ideas "in great measure." Impression of pain gives rise to an idea of pain, which in turn gives rise to impressions of "desire and aversion, hope and fear, which may properly be called impressions of reflection, because derived from it." 1.3.1 Of Knowledge KEY POINT: Knowledge and certainty confined to relations depending entirely on the ideas which we compare together. Resemblance Contrariety (e.g., existence and non-existence) Degrees in quality Proportions in quantity or number The first three are discoverable at first sight. Some of the others are, where the difference is very great. Where the difference is very little, we can only guess. In between, we have to use a more artificial manner. Geometry cannot give us certainty, but any error will be slight. So only algebra and arithmetic do. Abstract geometrical ideas are destroyed by the copy-principle: impressions are clear and precise, and so cannot give rise to copies that are dark and intricate. 1.3.2 Of Probability, and of the Idea of Cause and Effect KEY POINT: Reasoning is only required in the case of cause and effect. The other three relations may be present or not while the ideas remain the same. Distance is an example: change of place is not a change in the idea. We perceive identity and relations of time and place. We reason from the existence or action of one object to that of another. So apparent judgments of identity and distance of remote object involve cause and effect. What is the origin of the idea of causation? To reason justly using an idea, we must understand it, and to understand it, we must uncover its origins to a primary impression. "The examination of the impression bestows a clearness on the idea and the examination of the idea bestows a like clearness on all our reasoning. It is not a quality, since cause and effect is a universal relation, comprehending all specific qualities. So it is a relation. It is universally acknowledged that objects standing in the relation are contiguous, and this is essential to the relation. Not so universally acknowledged is priority. Simultaneous causation is ruled out by a tricky argument, which Hume says is of no importance. But now we are at a stand. All we observe is change in a given instance. How could we say that impulse, for example, produces motion, without invoking causation? But there has to be something more: necessary connection. Fine, but now what is the source of this impression? Hume drops the direct survey and proceeds indirectly through two questions: 1. Why do we find it necessary that the beginning of existence have a cause? 2. Why do we conclude that particular causes have particular effects? What is the nature of the inference drawn from one to the other, and of the belief we have that there will be the particular effect? 1.3.3 Why a Cause is Always Necessary KEY POINT: The opinion that a cause is always necessary is based on observation and experience, not on knowledge or any specific reasoning. It is not intuitively certain because certainty is restricted to present objects that are compared. A more general argument is that the ideas of a cause and a beginning of existence are separable (!) and so we see that there is no contradiction in supposing the latter without the former. Various attempts to prove the principle have been fallacious. (Hobbes, Clarke, Locke.) All are based on the fallacy that in supposing there is no cause, one is really assuming there is one (e.g. Locke, nothing can never be a cause). Nor can it be proved from the idea of an effect. So now the question is how reason and experience gives rise to such a principle? But Hume decides to "sink" this question in the second original question. "It will, perhaps, be found in the end that the same answer will serve for both questions." 1.3.4 Of the Component Parts of our Reasonings Concerning Cause and Effect KEY POINT: All causal reasoning begins in an impression of sense or an idea of memory (tantamount to an impression) and makes a transition to an idea of an existence which produced it. An example of history is given. The effect is the letters in the history book present to us. A regress argument is given to support the general point. 1.3.5 Of the Impressions of the Senses and Memory KEY POINT: The belief or assent given to the senses and memory as opposed to imagination is due entirely to the vivacity of the perceptions they present. For sensation, we do not know what the cause is, and we draw assurance from coherence. For memory, it can easily be confused with imagination. 1.3.6 Of the Inference from the Impression to the Idea KEY POINT: In examining the inference we discover constant conjunction. This is the missing third component of the relation of cause and effect, discovered serindipitously, by looking at the inference. But how does this advance us toward an understanding of necessary connection? "It seems evident, at least at first sight, that by this means we can never discover any new idea and can only multiply, but not enlarge, the objects of our mind." From mere repetition, no new idea can arise. Maybe something will turn up later, so we press on. Does the experience produce the idea by means of the understanding or the imagination. If it is by reason, it would have to be by the principle that experienced instances resemble unexperienced ones, and that the course of nature is always uniform. But what does this principle rest upon? It is not known. It cannot be demonstrated, since an exception can always be conceived. It is not based on probable reasoning. Probability requires this principle itself. "The same principle cannot be both the cause and the effect of another, and this is perhaps the only proposition concerning that relation which is either intuitively or demonstrably certain." If you try to use explanatory reasoning, you have to invoke cause and effect, though perhaps under the guise of "production." This might seem like question-begging, by assuming a key part of Hume's system, so he produces a second argument. Suppose that the production of an object in a single instance requires a power. But it has been shown that the power does not reside in the qualities. So how can we project from the appearance of the qualities that the power is there in other instances? So reason fails us not only in discovering the ultimate connection of causes and effects, but also in the extension beyond past experience. We suppose a resemblance, but we are never able to prove it. The mind, then, in passing from an impression to an idea, is determined by principles of association in the imagination. Reflection may play a part in cases of "other associations of objects which are more rare and unusual." In fact, sometimes reflection produces "custom" in "an oblique and artificial manner." This is the case of "knowledge of a particular cause merely by one experiment, provided it be made with judgment and after a careful removal of all foreign and superfluous circumstances." But custom is in fact drawn upon, namely the custom that establishes the presupposed general principle "that like objects, placed in like circumstances, will always produce like effects." So, "In all cases we transfer our experience to instances of which we have no experience, either expressly or tacitly, either directly or indirectly." An objection, traced to the inexactitude of the terms used, is now raised. (It is supposed to be based on an ambiguity in 'strong' and 'lively,' but it really seems to be based on an ambiguity in the use of the term 'idea.') One has an idea of which one has forgotten the corresponding impression. Now this idea leads us to believe that there was such an impression. The belief would have to have come from the idea, not the impression, which seems to contradict Hume's principle. The answer is that force and vivacity of the belief are taken from the idea, which "supplies the place of an impression and is entirely the same so far as regards our present purpose." This is because we consider it qua "a real perception of the mind of which we are intimately conscious" rather than as "the representation of any absent object." As a perception, the idea has a vivacity that can be transferred. The resemblance of an idea (idea of an idea) is superior in force to "the loose conceptions of the imagination." We find in it a certain je-ne-sci-quoi which we cannot describe, which makes us identify it as a memory. 1.3.9 Of The Effects of Other Causes of Relations KEY POINT: Resemblance and contiguity play a role in enlivening ideas which confirms the account of belief. The theory, in its novelty, ought to be given justification from as many sources as possible, and it ought to stand up to objections. An objection: resemblance and contiguity both meet the general description of principles of transmission. So why don't they produce belief? The mind forms two systems of realities. The first is from ideas of memory, which are relatively vivid. The second is from relating these to other ideas through the custom of cause and effect. This is the role of judgment, as in when I form an idea of Rome. Now resemblance and contiguity play an enlivening role, which is to "assist that [relation] of cause and effect and infix the related idea with more force in the imagination." It can even enliven a feigned idea. Still, the influence is "very feeble and uncertain." It does not give us the persuasion of real existence. The connections are variable and a matter of caprice. We go so far as to adopt a general rule "against proposing any assurances in those momentary glimpses of light which arise in the imagination from a feigned resemblance and contiguity." But the causal relation is different: it determines the mind's transition "without any choice or hesitation." This can be turned into a proof of Hume's doctrine. If we can show how resemblance and contiguity have some effect, augmenting the conviction and its vivacity, it shows how belief is a matter of vivacity. 1. Contiguity. Pilgrims to the holy land are more zealous believers. 2. Resemblance. Hume poses the interesting case of communication of motion by impulse. That this occurs cannot be proved, since we can conceive of many "consistent and natural" different outcomes. So why do we expect motion upon impulse? Because the effect resembles the cause. "Resemblance, then, has the same or a parallel influence with experience and, as the only immediate effect of experience is to associate our ideas together, it follows that all belief arises from the association of ideas, according to my hypothesis." Another example is the more vivid idea we get of the vast extent of the ocean by looking at it. Credulity is also best explained by appeal to resemblance. Experience teaches us the principles of human nature from which we gather the veracity of men as well as other things. Yet we seldom regulate ourselves by it, believing in all kinds of prodigious events. This is explained by alleged resemblance between the ideas people have and the alleged facts which they report. Looking at it in the other direction, there is a lot of real incredulity among the vulgar about a future state. The reason is that it bears so little resemblance to our current state. It is not because death is off in the future, since people are quite concerned about what will happen on earth after they die. A good example is the way Catholics condemn massacres, even while believing that the infidel will burn in hell. "All we can say in excuse for this inconsistency is that they really do not believe what they affirm concerning a future state, nor is there any better proof of it than the very inconsistency." Another point is that we can stand the stories of terror from the pulpit and in dramatic performances, but we can't stand fear and terror in real situations. Education: a second kind of custom. An idea by being repeated becomes entrenched and easily distinguishable from "any new and unusual idea." Sometimes it becomes so vivid that it overcomes what is the result of "the constant and inseparable union of causes and effects." Indoctrination could not produce belief it were the product of judgment. Many other instances are given: servants feeling the presence of the dead master, people who become familiar with someone by hearing about them. One-half of all beliefs have a basis in education, and they overwhelm beliefs from abstract reasoning and experience. Because education is contrary to reason, philosophers do not put it on a par with causal reasoning, as it should be. (Footnote 14. Imagination is sometimes contrasted with memory, based on its relative faintness. When it is contrasted with reason, it is the same faculty, but now taken in a stricter sense, excluding reasonings, demonstrative and probable.) 1.3.12 Of the Probability of Causes KEY POINT: There are three sorts of probability of causes. The first is due to not enough cases, the second to contrary cases, the third to cases that are not perfectly resembling. Examination of the probability of chances (in Section 11, not reprinted here) helps us understand the probability of causes. Chance is only a secret and concealed cause, according to the philosophers. All the several kinds of probability of causes have their origin in the association of ideas from present impressions. 1. This association acquires force from more instances. The inferior degrees of force are the degrees of probability. 'The gradation, therefore between probabilities to proofs is in many cases insensible, and the difference between these kinds of evidence is more easily perceived in the remote degrees than in the near and contiguous." As we mature, however, we cease to need a number of cases to build up the degree of assurance. We can make an inference from a single case, so long as it is "duly prepared and examined." Yet we do not claim certainty because of past instances of contrariety. 2. The second species of probability is due to the fact that we do not smoothly accumulate cases without exceptions. This obliges us to "vary our reasoning on account of this uncertainty and take into consideration the contrariety of events." Why does this contrariety exist? The vulgar attribute it to a failure of causal influence, but philosophers point instead to minute and remote springs and principles as at least the possible causes of contrariety. This is converted into certainty when it is seen upon close examination that when there are contrary effects, there are contrary causes, e.g., a grain of dust that stops the movements of a watch. "From the observation of several parallel instances, philosophers form a maxim that the connection between all causes and effects is equally necessary and that its seeming uncertainty in some instances proceeds from the secret opposition of contrary causes." We are finally able to return to the main thread, which concerns the nature of our idea of necessity, after the detour through the way we make particular causal judgments. The problem was to find the impression of which the idea is a copy. Hume's procedure now is to note that the idea of cause and effect is associated with necessary connection. There are relations of contiguity and precedence. When we reason, we enlarge our view due to repetition. There is nothing in the objects that makes any difference, but there is a difference nonetheless in the later cases. The difference is the determination of the mind by custom to produce a strong idea of the second object. "It is this impression, then, or determination, which affords me the idea of necessity." Hume optimistically thinks the reader will find this somewhat obvious given the strength of his argument, but he warns us not to think it as containing "nothing extraordinary nor worthy of our curiosity." But it is really "one of the most sublime questions of philosophy, namely that concerning the power and efficacy of causes, where all the sciences seem so much interested." So Hume will oblige the reader with a fuller account, which he thinks will bolster his position. (More) Hume discounts the previous attempts to give an account of the power of causes, based on his denial of innate ideas and adoption of the copy principle. In both the external and internal worlds, all we perceive is constant conjunction. There is also an argument based on the denial of abstract idea. The idea of a power would have to come from that of specific cases of causality, but we cannot find causality in the objects. The problem with the earlier philosophers is that they misapplied the idea of power. Hume then gives an account of their proper application. We don't get the idea from one instance, only several instances. Does repetition alone produce or discover power? No, since we cannot demonstrate that it exists. And it produces nothing new. So the source must be subjective: "the observation of this resemblance produces a new impression in the mind, which is its real model." As this effect is the only product of resemblance, it is identical to power or efficacy. A remarkable comparison is made between the necessity of cause and effect and the necessity of mathematical truths, which "lies only in the act of the understanding by which we consider and compare these ideas." This is the most violent paradox posed by the book. Hume is worried that biases of the mind will prejudice his readers. This bias is due to the "great propensity" of the mind "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 our senses." (Secondary qualities are an example.) The objection will be that Hume reverses the order of dependence between thought and causes. All he can answer is that the entrenched vie3w is meaningless. Finally, we get a definition of cause and effect, after having proceeded preposterously by using the terms before defining them. Philosophical relation (comparison between ideas) or natural relation (association between ideas.) 1. "An object precedent and contiguous to another and where all the objects resembling the forer are placed in like relation of precedence and contiguity to those objects which resemble the latter." 2. "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 impressio of the one to form a more lively idea of the other." Four corollaries: 1. All causes are the same kind, contrary to Aristotle. 2. There is no difference between "moral" and "physical" necessity. Nor is there a Lockean distinction between power and its exercise. 3. By the first definition of cause, there is no absolute or metaphysical necessity that every beginning has a cause. This is even more so on the second definition. "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." 4. If we have no idea of an object, we can never have reason that it exists. This will be later applied to "matter" and "substance." A full knowledge, though, is not requisite, "but only of those qualities of it which we believe to exist." 1.3.15 Rules by Which to Judge of Causes and Effects KEY POINT: Because it is possible for anything to cause anything else, general rules are needed to determine the philosophical relation of cause and effect. 1. Contiguity in space and time. 2. Priority 3. Constant union 4. Same cause always produces same effect. And some corollaries and further rules. This is all the logic we need in all philosophy, moral or natural. 1.4.1 "Of Skepticism with Regard to Reason" KEY POINT: If left to reason alone, probability would decrease to nothing if we check our reasoning. It is the strain of examination that keeps this from happening. Reason is a natural cause of which truth is the natural effect. But other causes may interfere, which means that we cannot trust that the cause actually operated in a given case, but must check whether it did. So "all knowledge degenerates into probability, and this probability is greater or less according to our experience of the veracity or deceitfulness of our understanding and according to the simplicity or intricacy of the question. This is seen in mathematics, where checking increases the probability, which itself "is derived from the constant union of causes and effects according to past experience and observation" (289). This holds in practical calculation as well. Even if we control for simplicity and get it down to a single calculation, it is questionable how high the sum must be before we have a mere probability. But this fuzziness is intolerable, as knowledge and probability are of different kinds, so Hume comes down on the side of probability (but without certainty of that). So what is the foundation of probability? In every judgment, of knowledge or probability, we ought to correct the first judgment about the object by a higher-order judgment "derived from the nature of our understanding" (e.g., whether we are wise and experienced or foolish, etc). Even with the greatest wisdom and experience, one is susceptible for many errors. So this provides a new standard of probability to correct the first one. Reason now obliges us to add "a new doubt, derived from the possibility of error in the estimation we make of the truth and fidelity of our faculties." This doubt arises naturally. Even if it is favorable to the judgment we made about our understanding, it still increases the initial doubt and so weakens our first evidence. [Though it is hard to say how.] The process continues in infinitum. But because the initial probability is a finite object, it must eventually perish under infinite decrease. "All the rules of logic require a continual diminution and at last a total extinction of belief and evidence" (290). Does Hume assent to this argument, and does it make him a skeptic (holding "that all is uncertain and that our judgment is not in anything possessed of any measures of truth and falsehood")? No, because nobody is a skeptic, due to the "absolute and uncontrollable necessity" of nature to determine us to judge. There is no antagonist to someone who tries to defeat total skepticism. What this argument does is to confirm the hypothesis concerning belief. If belief were "a simple act of thought, without any peculiar manner of conception or the addition of force and vivacity," it would be destroyed by the use of reason. Since we continue to believe despite the argument, belief is "a peculiar manner of conception which it is impossible for mere ideas and reflections to destroy" (291). Hume has not yet said how belief is preserved, however. The same principles apply to the higher- order judgments as apply to the original. The way it works must be that some of our impressions have qualities that work hand-in-hand with qualities of the imagination. "It will therefore be easy for us to discover these qualities by a comparison of the impressions to which we attribute a distinct and continued existence with those which we regard as internal and perishing." The difference is not in the vulgar criteria of involuntariness or vivacity, since these qualities are found in pains, pleasures, passions and affections. The first viable quality of impressions regarding continued existence is constancy. Impressions appear in the same order even after interruption of perception. But constancy is not enough, given that bodies change their positions when we are not perceiving them. Still, they preserve coherence, which provides a foundation for "a kind of " causal reasoning that establishes belief in their continued existence. So how do constancy and coherence give rise to belief in continued existence? (Distinct existence will be a consequence of this.) Coherence is first. An extended example is given. 1. I hear "a noise as of a door turning upon its hinges." If this noise is not from the door, it contradicts all past experience. 2. I see a porter moving toward me. If the porter did not come up the stairs, it contradicts all past experience, according to which bodies have gravity and so he did not levitate to the next floor. 3. I receive a letter. If the letter did not traverse the sea and was not handed off at various posts and travel in different vehicles, it contradicts past experience. So the supposition of continued existence is the only one that will prevent these contradictions. "Here, then, I am naturally led to regard the world as something real and durable and as preserving its existence even when it is no longer present to my perception" (297). Although this seems similar to causal reasoning, it is not, because there is nothing that is associated regularly in our minds but perceptions. Moreover, our supposition is actually more regular than our associated perceptions, which custom could not account for. We turn our heads and our perception does not present the body we were looking at before, etc. "Any degree, therefore, of regularity in our perceptions can never be a foundation for us to infer a greater degree of regularity in some objects which are not perceived, since this supposes a contradiction, namely, a habit which was never present to the mind." So we need some other principles. The principle invoked is that of a kind of inertia, where "the imagination, when set into any train of thinking, is apt to continue even when its object fails it and, like a galley put in motion by the oars, carries on its course without any new impulse" (297). The mind observes uniformities and "naturally continues" until the train is as uniform as possible. "The simple supposition of their continued existence suffices for this purpose." Now Hume says that the kind of continued existence we get out of coherence is not nearly enough to support a system the continued existence of all bodies. Constancy will be needed, also to establish continued existence. But because this "will lead me into a considerable compass of very profound reasoning," he will first sketch his account of how it works and then draw consequences from it. What happens in our minds is that our perceptions are interrupted, yet constant to a certain degree. It cannot be the same perception that re-occurs after the interruption, but rather an entirely new one. This creates a conflict ("a kind of contradiction") in our imaginations: we want to regard the perception as the same but we must regard it as different. To overcome the conflict, we "disguise, as much as possible, the interruption, or rather remove it entirely by supposing that these interrupted perceptions are connected by a real existence of which we are insensible" (298). This supposition of continued existence gets a force from memory and the tendency to regard perceptions of the same. This results in belief, which just is a vivid idea. Now this system has only been sketched, not justified. To do this, Hume needs to do several things. 1) The problem arose because of the non-identity of interrupted perceptions. So he needs to say what the "principle of identity" is. The principle is unvaried uninterruptedness, since identity is temporal endurance. 2) Explain why the resemblances in interrupted perceptions impel us to attribute identity to them. Interrupted perceptions have only unvariedness. They may be interrupted by a long period of time. We think with the vulgar here: there is no double-existence involved, but "only a single existence, which I shall call indifferently object or perception, according as it shall seem best to suit my purpose." This is what the vulgar understand by shoe, etc. Resemblance greases the transitions in the imagination better than anything else. Hume adopts the general rule "that whatever ideas place the mind in the same disposition or in similar ones are very apt to be confounded." When there is an uninterrupted perception, moments pass from one to another without any new perception being generated. Can some other objects put us in the same disposition? If so, then by the general rule, they are easily confused with identical objects. The answer is easy: "related" objects can do the same thing. "The thought slides along the succession with equal facility as if it considered only one object, and therefore confounds the succession with identity" (300). This is what happens in perception. We have great constancy across interruption. The result is an easy transition which produces "almost the same disposition of mind with that in which we consider one constant and uninterrupted perception. It is therefore very natural for us to mistake the one for the other" (300). 3) Give an account of the propensity to unite the broken perceptions. It is a certain principle that whenever there is conflict in the mind (with the sentiments or passions), there is uneasiness. The converse holds as well: what "strikes in with the natural propensities and either externally forwards their satisfaction or internally concurs with their movements is sure to give a sensible pleasure" (301). So there is uneasiness in the present conflict between identity and interruptedness. Which one is to give way? The "smooth passage of our thought" moves us toward identification, so we give up the interruptedness. Yet this does not seem satisfactory, in that with long intervals, the perceptions are obviously interrupted. So it appears contradictory that they continue to exist without a mind. To "clear up this matter," Hume will try to show that interruption in appearance of a perception dies not necessarily imply an interruption in its existence! He does not challenge the claim that the objects are the perceptions. So he needs to show: A. How a perception can be absent from the mind without ceasing to exist. The mind is a bundle of perceptions, and any one perception may be broken off from it without ceasing to exist. B. How can an idea become present to the mind (return to it?) without being a new existence. The broken-off idea can be returned to the bundle at a later time. "The same continued and uninterrupted being may, therefore, be sometimes present to the mind and sometimes absent from it without any real or essential change in the being itself" (301). This just establishes the possibility of the continued existence of perceptions, the lack of a contradiction. But the mind has no access to this, so it feigns continued existence. 4) Explain the force and vivacity of the resulting idea. This supposition of continued existence amounts to belief. This is explained by the smoothness of the transition, wherein the vivacity of the original impression is retained "without any great diminution" (302). The same holds for vivid ideas of memory. Finally, we extend this beyond sensation and memory because "objects which are perfectly new to us and of whose constancy and coherence we have no experience" because of their resemblance to constant and coherent perceptions. Section 4: Of the Modern Philosophy KEY POINT: The fundamental principles of the modern philosophy, that ideas of primary qualities resemble their objects while ideas of secondary qualities do not, is mistaken. There are two kinds of principles of the imagination, those that "are permanent, irresistible, and universal, such as the customary transition from causes to effects and from effects to cause, and the principles which are changeable, weak and irregular" (309). The changeable, etc. principles are subject to skepticism. The former are "the foundation of all our thoughts and actions so that upon their removal, human nature must immediately perish and go to ruin" (309). Voice in the dark are thought to be other persons. But some people apprehends specters instead. The principles of the ancient philosophers are like specters in the dark. "The modern philosophy pretends to be entirely free from this defect and to arise only from the solid, permanent, and consistent principles of the imagination." What are the grounds of this pretension? Its fundamental principle is that heat, colors, etc. are impressions in the mind and do not resemble the objects causing them. Its chief argument is that from relativity. The external object remains the same while the impressions vary. The conclusion drawn from this is "as satisfactory as can possibly be imagined." The key claim is that like effects have like causes. Since some impressions do not resemble their originals, and since there is no difference among these and other impressions, none do. "We conclude, therefore, that they are, all of them, derived from a like origin." It seems that the principle of primary qualities alone being real follows by an "easy consequence." These are "extension and solidity, with their different mixtures and modifications, figure, motion, gravity , and cohesion." These are supposed to explain all physical phenomena. Many objections may be lodged against the system, but this one is in Hume's opinion "very decisive." Hume claims that if we grant that colors have no mind-independent existence, the so-called primary qualities must also be. Motion is resolved into extension and solidity. But extension is resolved into "perfectly simple and indivisible" parts, which must be colored or extended. But color is excluded from real existence, so they must be solid. But to have an of solidity, we must have an idea of objects which do not penetrate each other despite the utmost force. But how is this to be composed? Not of colors, etc. And extension depends on solidity, as we have seen. So the idea of solidity requires circular reasoning. Though this argument "will appear entirely conclusive to everyone who comprehends it," it is abstruse and could use some further explanation. In effect, Hume recapitulates the argument (311). Another problem is the impressions from which the idea of solidity is supposed to be derived. It is supposed to come from feeling. "But this method of thinking is more popular than philosophical" (311). The feeling is different from the solidity. First, someone who cannot feel the table can see his hand to be supported by it. Feeling is the outcome of a complex mechanical process. Second, impressions of touch are simple. Yet to replicate the situation where two stones resist each other, we would have to remove part of the impression, which is impossible. Third, solidity is invariable, while the feeling of resistance is variable. The conclusion is that there is an opposition between causal reasoning and the senses. The former excludes colors, etc, which then gets rid of the very objects that the senses indicate "have a continued and independent existence." The unstated conclusion is that the modern philosophy is mistaken. Section 5: Of the Immateriality of the Soul KEY POINT: The notion of an immaterial soul is meaningless, and given the account of causality in Part III, the matter may be the cause of thought. However, this has no effect on religion. The contradictions found with respect to external perceptions will surely extend to internal ones, which are inclined to think are even more obscure. Not so: it at least contains no contradiction. "What is known concerning it agrees with itself, and what is unknown we must be contented to leave so" (312). What about the substance of the soul? To have a resembling impression of it is impossible, "since, according to this philosophy, it is not a substance and has none of the peculiar qualities or characteristics of a substance." Speaking of actuality, rather than possibility, Hume asks what kind of impression it is supposed to be: sensation or reflection, pleasant or painful, enduring or transient? With no answer to these questions, the proponent of substance may revert to abstract definitions, such as "something which may exist by itself." But everything satisfies this definition. Since whatever is different is distinguishable, and whatever is distinguishable is separable by the imagination, we can think of anything, call it mode or accident, existing separately. "They are, therefore, substances, as far as this definition explains a substance" (313). So we should drop the dispute about the materiality or immateriality of the soul. We have no idea of a substance, and we do not need inhesion to understand the existence of a perception. Hume then argues that the doctrine of the immateriality of the soul makes Spinozism a viable option. Everything that is said about the soul as substance applies to Spinoza's hyper-substance. Philosophers think that they have established that material things cannot be the cause of thought, as this power cannot be discovered in them, no matter how they are divided or organized. But in fact, no power can be discovered in anything. Even God would have to be considered bereft of power. Or, if God is said to be the power moving everything (Malebranche), then God is the author of evil. All we have is constant conjunction. But there is constant conjunction between changes in the matter and changes in thought. So we must think of changes in matter to be causes of changes in thought. Finally, there is the issue of the immortality of the soul. Here, philosophy must make an apology for herself. Although the metaphysical arguments for the immortality of the soul are no good, there are moral and analogical arguments which are good and which are not affected by the present system. Section 6: Of Personal Identity Philosophers think we have a strong sense of the self, and that each emotion, etc. confirms that it exists and continues to exist. But they are contrary to experience. Once again, where is the impression? To produce one would be to invite contradiction, since it would have to remain the same all over our life, while there is no constant and invariable impression. Also, all perceptions are distinct and so capable of existing on their own. So how do they belong to the self? All Hume can find are individual perceptions. Annihilate them, and you annihilate the self. Anyone who does not have this impression ("the rest of mankind") is a bundle of perceptions in perpetual flux and rapid succession. "The mind is a kind of theatre where several perceptions successively make their appearance, pass, repass, glide away, and mingle in an infinite variety of postures and situations." There is no identity or simplicity here, not even a theatre! So why do we ascribe identity to successive perceptions? Here we have to take the matter pretty deep and look into the identity of animals and plants, since there is a great analogy here. Once again, the operative feature is the smoothness of transition. Although identity applies only to what is invariable and uninterrupted, when there is enough similarity, we confuse identity with the notion of related objects.