G. J. Mattey’s Notes on Hume’s Treatise, Book I, Part I, Section 1

Notes on Hume’s Treatise

by G. J. Mattey

Book 1
Of the UNDERSTANDING
PART 1
Of ideas, their origin, composition, connexion, abstraction, &c.

Sect. 1. Of the origin of our ideas.

This section begins the author’s investigations of the human understanding, which in turn initiate his science of human nature.

Locke’s stated goal was to investigate the human understanding, with the end of inquiring “into the original, certainty, and extent of human knowledge, together with the grounds of belief, opinion, and assent” (Introduction). To do this, he is “to consider the discerning faculties of a man, when they are employed about the objects which they have to do with.” His first task is to find the origin of these objects “which a man observes, and is conscious to himself he has in his mind.” In conjunction with this task, he is to show “the ways whereby the understanding comes to be furnished with them.”

Following Descartes, Locke calls the objects of the human understanding “ideas.” He describes ‘idea’ as “the term which, I think, serves best to stand for whatsoever is the object of the understanding when a man thinks . . . or whatever it is that the mind can be employed about when thinking.” In Chapter 1 of Book II, he writes, “Every man being conscious to himself that he thinks; and that which his mind is applied about whilst thinking being the ideas that are there, it is past doubt that men have in their minds several ideas . . . .” The origin of ideas is to be found in experience, as Locke had argued in Book I that there are no innate ideas. The mind at birth is like white paper, ready to be written upon by experience.

Ideas are further classified as being either simple or complex. A simple idea contains “nothing but one uniform appearance, or conception in the mind” and is not distinguishable into different ideas. It cannot be invented by the mind, nor can it be destroyed by the mind. Simple ideas are the building-blocks of complex ideas: “When the understanding is once stored with these simple ideas, it has the power to repeat, compare, and unite them, even to an almost infinite variety, and so can make at pleasure new complex ideas.”

1. The perceptions of the human mind are divided into two kinds: impressions and ideas. All perceptions “strike upon the mind, and make their way into our thought and consciousness.” They may do so with different “degrees of force and liveliness.” Impressions are those which strike with the most “force and violence.” Included under the impressions are all sensations, passions, and emotions. A qualifier is added, “as they make their first appearance in the soul.” This seems to leave open the possibility that there are sensations, passions, and emotions which are in the mind at a later time, and which may not be impressions. By contrast, ideas are “the faint images of these [impressions, or perhaps sensations, passions, and emotions] in thinking and reasoning.” This characterization makes it seem that ideas are to some extent intellectual in a way that sensations, passions, and emotions are not. An example of ideas is given: “all the perceptions excited by the present discourse,” with the exception of the perceptions of sight and touch produced by our interaction with the book, and with the further exception of “the immediate pleasure or uneasiness” which reading the book might bring about. We are told that not much explanation of this distinction is needed, since “every one of himself will readily perceive the difference betwixt feeling and thinking.” This once again seems to indicate that ideas are in some way intellectual in character, while impressions are not. The degrees of force and liveliness which distinguish impressions and ideas are generally quite different, but in some cases the relative degrees of liveliness of the two may be very close. On the one hand, ideas may be nearly as lively as impressions “in sleep, in a fever, in madness, or in any very violent emotions of soul.” On the other hand, impressions may be “so faint and low, that we cannot distinguish them from our ideas.” Because these cases are rare, no one would fail to distinguish the two types and give them different names.

Footnote. The author notes that his use of the term ‘idea’ differs from that of Locke, who used it to denote “all our perceptions.” In so doing, Locke “perverted” the notion, and the author is “perhaps” restoring the original sense to the word ‘idea.’ By this, he seems to mean the sense in which an idea is something intellectual. Further, the word ‘impression’ is not used in the ordinary sense, which expresses “the manner, in which our lively perceptions are produc’d in the soul” [that is, that the lively perceptions are “impressed” on the soul]. Instead, it is used to indicate only the perceptions themselves. The author finds that there is no name in English or any other language for this class of perceptions.

2. A second division of perceptions is useful and applies to both impressions and ideas. Simple impressions and ideas “admit of no distinction nor separation” into parts. This is a very important point for the author, who will later draw important consequences from cases where ideas are separable into components. Complex impressions and ideas, by contrast, may be distinguished into parts. The example the author uses is surprising. It is easy, he says, to distinguish the color, taste, and smell of an apple, despite the fact that they “are qualities all united together” in it. An apple is not a perception, or at least so one would think without reading further in the Treatise. One would have expected the example to concern the impression or idea of an apple. [John Locke, in An Essay concerning Human Understanding, Book II, Chapter 8, Section 8, explicitly notes that he understands ideas (Hume’s “perceptions”) “sometimes as [being] in the things themselves,” by which he means “those qualities in the objects which produce them [the ‘ideas’] in us.”]

3. Now that we have a matrix of four kinds of perceptions, it is time to “consider with more accuracy” the qualities and relations of the four kinds. A striking relation is the great deal of resemblance between impressions and ideas. [See Section 5 for a general discussion of the relations of perceptions.] Indeed, the only way in which they differ is with respect to their “degree of force and vivacity.” Ideas seem to be, in a way, “reflections” of impressions, “so that all the perceptions of the mind are double.” An example is shutting my eyes and thinking about my room. In so doing, I form ideas, which are “exact representations of the impressions I felt” when my eyes were open. Everything about the idea (except its degree of liveliness) is to be found in the impression as well, and vice-versa. One finds the same “resemblance and representation” in other perceptions as well. “Ideas and impressions appear always to correspond to each other.” Now it begins to emerge that ideas as objects of thought are very much like sensations, passions and emotions, and in particular are not abstractions. [See Section 7 for a general discussion of abstract ideas.] The correspondence of ideas and impressions “seems to me remarkable, and engages my attention for a moment.”

4. But “upon a more accurate survey,” the author retreats from the general claim of the last paragraph, “that all our ideas and impressions are resembling.” The problem is that it does not take account of the distinction between simple and complex perceptions. Many complex ideas do not resemble any complex impressions we have. An example is “the New Jerusalem, whose pavement is gold and walls are rubies.” The author has an idea of such a city, by imagining it, but he has never seen such a thing. Conversely, many complex impressions do not correspond very well to complex ideas. The example here is the complex impression of Paris, the complex idea of which does not “perfectly represent all its streets and houses in their real and just proportions.” In the first example, an explicit connection is made between ideas and imagining. It seems that some complex ideas, which we are to understand as being the objects of thought, may be products of the imagination.

5. So for complex perceptions, while there is “in general a great resemblance” between complex impressions and complex ideas, they are not always copies of one another. In the case of simple perceptions, however, the rule that the idea is an exact copy of an impression holds “without any exception.” An idea of red formed in the dark differs from an impression of red formed in daylight, and they “differ in degree, not in nature.” It is impossible to enumerate all the cases of resemblance, but the reader is invited to experiment with as many cases as he wishes. Anyone denying the principle of resemblance between simple ideas and simple impressions should provide an example of a simple impression not resembling its corresponding simple idea, or vice-versa. “If he does not answer this challenge, as ’tis certain he cannot, we may from his silence and our own observation establish our conclusion.”

6. The general thesis is that the “two species of perceptions,” ideas and impressions, “are exactly correspondent.” The reason is first, that all simple ideas resemble simple impressions, and vice-versa, and second that all complex ideas and impressions are formed from simple ideas and impressions. This discovery “requires no further examination,” so it is now time to look for other qualities of the relation of ideas and impressions. Specifically, there is the question of the existence of ideas and impressions and “which ideas and impressions are causes, and which effects.”

7. The subject of the Treatise as a whole is the “full examination of this question.” Because the whole book will be devoted to the question, in the present section the only task will be to establish a single general proposition: “that all our simple ideas in their first appearance are deriv’d from simple impressions, which are correspondent to them, and which they exactly represent.” [Since it has already been established that the ideas correspond to and exactly “represent” simple impressions, the only issue remaining is whether the ideas are “derived from” the corresponding impressions.]

8. The author discovers only two kinds of phenomena to prove the general proposition stated in the last paragraph, that all simple ideas, when they first appear, are derived from simple impressions which they exactly represent. The first phenomenon is the observation of the constant conjunction of impressions and ideas and of their order of precedence. The second phenomenon, which is described in the next paragraph, concerns the consequences of defects of the faculties that supply us with impressions. In both cases, the phenomena which fall under the two kinds are “obvious, numerous, and conclusive.” The fact that simple ideas are constantly conjoined with corresponding simple impressions has already been argued. The new conclusion to be drawn from the constant conjunction is that “there is a great connexion betwixt our correspondent impressions and ideas, and that the existence of the one has a considerable influence upon that of the other.” The basis of the conclusion is that the “infinite” number of cases of conjunction of simple impressions and resembling ideas “can never arise from chance; but clearly proves a dependence of the impressions on the ideas, or of the ideas on the impressions.” [The nature of the kind of “proof of dependence” is discussed further in Part 3, especially Section 6, whose result is quite surprising.] Now the only question remaining is whether the impression depends on the idea, or the idea on the impression. This question is answered by observation again: it is impressions that always make the “first appearance,” something ideas never do. To teach a child an idea, say of orange, we present the child with an orange object, which is to convey to the child an impression of orange. It is absurd to try to teach the child what orange is by exciting an idea of the child’s mind of orange, which would in turn produce an impression of orange. “Our ideas upon their appearance produce not their corresponding impressions, nor do we perceive any colour, or feel any sensation merely upon thinking of them.” [That is, if I think of orange, there is no way that I can make the idea vivid enough to convert it into an impression.] “On the other hand we find, that any impression either of the mind or body is constantly follow’d by an idea, which resembles it, and is only different in the degrees of force and liveliness.” The constant conjunction of impressions and ideas affords “a convincing proof” of there being a relation of dependence, and the order of precedence affords an equally convincing proof of the fact that it is the impressions that are the causes of the ideas, and not vice-versa.

9. The second kind of phenomenon is now brought forward “to confirm this.” This phenomenon is “plain and convincing.” Whenever there is a circumstance in which the faculty which ordinarily produces a kind of impression (e.g. vision, which produces impressions of colors) does not produce the impression, “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.” This happens in cases where a person is born blind or deaf, as well as in cases where the faculties have not been stimulated so as to produce a particular kind of impression. The author uses an example from Locke’s Essay (Book II, Chapter 1, Section 6) to illustrate the point. Someone who has never tasted a pineapple (and thus had an impression of its taste) has no idea of that unique taste.

10. This paragraph contains the famous “missing shade of blue” example. Although the author has “proved” that there is a dependence of simple ideas on simple impressions, he announces that there is “one contradictory phænomenon, which may prove, that ’tis not absolutely impossible for ideas not to depend on their correspondent impressions.” To set up the case, the author notes that there are various distinct shades of colors or sounds which, although resembling others, are “really different from them.” Thus blue resembles green but is not green. Similarly, different shades of one color, such as shades of blue, are distinct but resembling, and moreover are “independent of the rest.” The argument for this claim is by reductio. Suppose you deny that the ideas of colors are distinct and independent. Then it would be possible to start with the idea of one color and then generate ideas of all other colors [say, by imagining colors in the order of the color wheel]. Further, if it is denied that closely resembling shades are different, then it cannot be denied that the colors that least resemble each other are different. Now the author proposes a thought-experiment. Suppose that a person has lived for thirty years and has experienced all colors except for a single shade of blue. Now place all the colors before the person [thus yielding impressions of them] except for that shade. The person will “perceive a blank” and realize that there is a greater difference between the two colors flanking the missing color than there is between any two other colors. Now the question is whether it is possible for this person, “from his own imagination, to supply this deficiency, and raise up to himself the idea of that particular shade, tho’ it had never been convey’d to him by his senses.” The answer, according to the author, is that few people would believe that he could not do it. [Perhaps the author has in mind his account of colors to appear in Book II, Part II, Section 6. Colors “are susceptible of an entire union,” so that they “may be blended so perfectly together, that each of them may lose itself, and contribute only to vary that uniform impression, that arises from the whole.” Then perhaps two ideas of colors could be blended together to form an idea of the missing shade.] This thought-experiment is then taken to “serve as a proof, that the simple ideas are not always deriv’d from the correspondent impressions.” This would seem to undermine the “general maxim” that “all our simple ideas in their first appearance are derive’d from simple impressions” (paragraph 7). Surprisingly, the author says that this example ought not to move us to change the general principle, because it is “so particular and singular.” By this apparently is meant that the power to raise an idea in this way is confined to very precise circumstances that are the exception, rather than the rule. Indeed, this kind of example is “scarce worth our observing.” So the general maxim stands.

11. There is a second limitation of the general principle that impressions are prior to ideas. Some ideas are themselves prior to other ideas, which are images of them. In those cases, it is an idea, not an impression, which is precedent. The author comments that “this is not, properly speaking, an exception to the rule so much as an explanation of it.” The rule states only that ideas “in their first appearance” are preceded by impressions. An impression produces a “primary” idea of which the “secondary” idea is an image. Thus, the general rule is already qualified so as to apply only to ideas dependent “immediately” on impressions, and not to those secondary ideas which proceed “mediately” from the primary ideas. But all ideas depend either immediately or mediately on impressions.

12. The principle of the dependence of simple ideas on simple impressions, and the resemblance of the one to the other, is “the first principle I establish in the science of human nature.” Although it is “simple in appearance,” it should not be despised. For this is a re-casting of the celebrated debate about whether there are innate ideas or whether all our ideas are derived from sensation and reflection. [See Locke’s Essay, Book I.] The proof of non-innateness has the following form. To prove that the idea of a color, for example, is not innate, the philosopher shows that it is “convey’d by our senses.” To prove that a the idea of a passion is not innate, he shows that we have a precedent experience of the given emotion. But all that the arguments can really prove is that “ideas are preceded by other more lively perceptions, from which they are deriv’d, and which they represent,” which is the author’s thesis. He expresses the hope that by clearly stating the question in this way, he will “remove all disputes concerning it, and will render this principle of more use in our reasonings, than it seems hitherto to have been.”

In the Enquiry concerning Human Understanding, Section 2, “Of the Origin of Ideas,” Hume goes over the same ground, although with a few differences. He divides all “perceptions of the mind” into “two classes or species”: impressions (“all our more lively perceptions”) and “thoughts or ideas,” “which are the less lively perceptions, of which we are conscious, when we reflect on any of those sensations or movements above-mentioned.” Examples of the sensations are “when a man feels the pain of excessive heat, or the pleasure of moderate warmth.” The “movements” are the way a person is “actuated” in “a fit of anger” or being in love: what Hume calls “sentiments and affections.” More generally, Hume describes a class of perceptions, “when we see, or feel, or love, or hate, or desire, or will.” Although the vigor of our ideas is such that we can “almost” say we see or feel” the object of our sensation, we can still distinguish ideas from sensations, unless we are disordered. Similarly, a normal person could not mistake the conception of anger or love from the sentiment itself, even though the conception be an accurate representation of the sentiment.

Hume goes on to note that the human mind seems boundless in what it can conceive, but at the same time “it is really confined within very narrow limits.” “All this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and experience.” For example, the conception (idea) of a virtuous horse is composed of the idea of virtue, which is conceived on the basis of “our own feeling” and that of a horse, which is conceived on the basis of our acquaintance through sensation of horses. The general principle Hume enunciates here is that “all our ideas or more feeble perceptions are copies of our impressions or more lively ones.”

To prove this thesis, Hume uses two arguments. The first is that analysis of ideas “however compounded or sublime” ultimately reveals simple ideas, and these simple ideas “were copied from a precedent feeling or sentiment.” Hume challenges the reader to provide a counter-example, where an idea is not copied from antededent impressions. His response would then have to be to produce the impression. The second argument is that people who lack the impression lack the corresponding idea as well. People may not have been a position to have the impression, may be incapable of a certain feeling. On the other hand, there may be beings with senses we do not have, and we humans would be unable to have the ideas tht they do.

The “missing shade of blue” counter-example is raised here as “one contradictory phænomenon, which may prove that it is not absolutely impossible for ideas to arise, independent of their correspondent impressions.” Here, the language is almost identical to that in the Treatise.

In a long footnote, Hume applies his copy principle to the case of the dispute over “innate ideas.” He claims that it is likely that the denial of innate ideas amounts to nothing more than the principle that all ideas are copies of impressions. Hume distinguishes three meanings of ‘innate,’ all of which yield different results.

Locke denied that there are innate ideas, but his denial was based on a conflation of ideas with impressions. As has been seen, impressions are innate (in the third sense), and Hume challenges anyone to deny that “self-love, or resentment of injuries, or passion between the sexes” are innate. [Note that all of these examples are cases of “sentiments” or “affections” of the mind, and not cases of sensation, which is less obviously “innate,” in the ordinary usage of the term.] Hume notes that Locke is prone to ambiguity throughout his writing, and conjectures that he was “betrayed into this question by the schoolmen, who, making use of undefined terms, draw out their disputes to a tedious length, without ever touching the point in question.”

In his Essays on the Active Powers of the Human Mind (1788), Reid criticizes the claim in paragraph 5 that the relation between impressions and ideas holds without any exception. He finds that this conclusion is formed by the author rashly and unphilosophically (p. 26). The basis of Reid’s objection is that the author’s claim is based on induction, which cannot be perfect (admitting of no exceptions) unless all simple ideas that could enter the human mind are examined, something which no one can claim to be able to do; and, therefore, no man can, consistently with the rules of philosophizing, assure us, that the conclusion holds without any exception (p. 26). The rules of the experimental method of reasoning, which the author endorses in the Introduction to the Treatise, require that any claim based on induction must not exclude exceptions in advance of further investigation. That is, exceptions must not be ruled out in advance. Reid cites Newton, who states that an inductive conclusion may be pronounced general so long as no exceptions have been found, but must be qualified, losing its generality, if exceptions have been found (Optics, Query 31).

The disastrous consequence of granting the exceptionless authority of this rule is to reject ideas of material and mental substance, space and duration, and power.