Context

Part IV of Book I consists in an examination of various “systems” of philosophy. Section 1 and 2 investigate skeptical systems, while Sections 3 and 4 look into accounts of the nature of the material world. In the previous section, the author completed the first part of his investigation of philosophical accounts of the human mind, by exploding the doctrine of the immateriality of the soul. In the present section, he turns to the issue of its identity over time and its simplicity.

Background

The subject of personal identity was treated extensively by Locke in Chapter XXVII of Book II of the Essay. According to Locke, the identity of an object over time is determined by continuation of its existence after it has begun to exist. Locke distinguished between the identity of a mass, which requires that all its parts remain in existence after the mass was formed, the identity of a living body, which consists in the organized relation of its parts, and the identity of a person, which is based on the ability to bring past ideas and actions into one’s present consciousness. “For as far as any intelligent being can repeat the idea of any past action with the same consciousness it had of it at first, and with the same consciousness it has of any present action; so far is it the same personal self.” On this view, personal identity can be construed as the product of memory, a claim which the author attempts to refute in paragraph 20.

The Treatise

1. Philosophers have held that we have an intimate consciousness of the self, which gives us a “certainty, beyond the evidence of a demonstration,” of its perfect identity and simplicity. They claim that the pain or pleasure accompanying each of our strongest sensations or passions focuses our attention upon the self and does not distract from our acquaintance with it. This claim itself cannot be proved, and the attempt to prove it would make it less evident, since we are not as intimately acquainted with any other fact. Moreover, if we were to doubt these claims about the self, there is nothing of which we can be certain.

2. But these claims made on the basis of our experience in fact contradict that experience, and we have no idea of the self of the kind described above. The reason we have no idea of the self is that ideas are copies of impressions (as claimed by the author in Book I, Part I, Section 1), and there is no impression of the self. For what could such an impression be? We must answer this question if we are to have a clear idea of the self, yet we cannot answer it without being involved in “a manifest contradiction and absurdity.” Every real idea must arise from a single impression. But the “self or person is not any one impression, but that to which our several impressions and ideas are suppos’d to have a reference.” Moreover, the requisite impression would have to “continue invariably the same,” given the idea of the self as perfectly identical. But “there is no impression constant and invariable.” All of our sensations and passions come and go in succession and they generally do not exist at the same time. So no one of these, no pain, joy, etc., could be the impression that gives rise to the idea of the self. Since these are all the impressions we have, “there is no such idea.”

3. Not only is there no idea of a perfectly identical self, but there is also no way to explain how such a self could be related to our “particular perceptions.” The author appeals implicitly to his principle that what is distinguishable is different, and what is different can be conceived to exist separately. If my particular perceptions are distinguishable from other particular perceptions, they may exist separately from them. And [in fact, they may be distinguished from anything else, so] they depend on nothing else for their existence and may exist apart from myself. And if they can exist apart from myself, then they do not depend on myself for their existence. The author goes further than this reasoning to claim that my particular perceptions do not depend on “any thing to support their existence,“ presumably because they may be distinguished from any thing. “After what manner, therefore, do they belong to self; and how are they connected with it?” he asks. He then recounts his own attempts to discover his self: when he looks for it, all he finds is particular perceptions, “of heat or cold, light or shade, love or hatred, pain or pleasure.” All he can observe is perceptions, and he never is able to “catch myself at any time without a perception.” Further, in the absence of perceptions, such as when he is asleep, he is completely oblivious to himself, “and may truly be said not to exist” [during that time]. The death of the body brings about permanent annihilation, as there would no longer be any perceptions at all, and the author contends that he cannot conceive of anything further “to make me a perfect non-entity.” He states that he cannot reason with anyone who claims to have, on “serious and unprejudic’d reflection,” “a different notion of himself.” Maybe such a person is right, and maybe that is because that person has an ability to “perceive something simple and continu’d,” but the author can discover no such power of perception in himself.

4. Regardless of whether there are metaphysicians who claim to be able to perceive a simple and continued self, the author claims that every other self is merely “a bundle or collection of different perceptions, which succeed each other with an inconceivable rapidity, and are in a perpetual flux and movement.” Our perceptions change quickly, whether it is due to the input of the senses or our even-more variable mental activity, and the author professes not to find any power of the mind that “remains unalterably the same, even for a single moment.” He famously describes the mind in this image: “The mind is a kind of theatre, where several perceptions successively make their appearance; pass, re-pass, glide away, and mingle in an infinite variety of postures and situations.” Properly speaking, there is no single time in which the mind is simple, nor is there any stretch of time in which it is identical, despite any natural propensity we might have to think it so. The author cautions, though that the metaphor of the theatre should not be taken too literally, as we have not the most distant notion of an analogue of the place where a show is staged or of the materials used to put it on.

5. We do have a great natural propensity to view the successive perceptions as in fact identical, “and to suppose ourselves possest of an invariable and uninterrupted existence thro’ the whole course of life.“ The author states that to explain this propensity, a distinction must be made between the identity of our imagination and understanding, on the one hand, and the identity of our persons regarding our passions and the concern we have for ourselves. It is the first kind of identity that is proper to Part I of Book I, “Of the Understanding.” [The passions and the basis of human action in general are the subject of Book II, though they are invoked at the end of paragraph 19 below.] Explaining the cognitive side of personal identity will require the author to “take the matter pretty deep” to give a perfect explanation of it. His first step is to account for the way in which we attribute identity [over time] to plants and animals, as there is “a great analogy betwixt it, and the identity of a self or person.”

6. The author begins by describing two relations that are “in themselves perfectly distinct, and even contrary.” The idea of the relation of identity or sameness is that of object’s existing in an invariable and uninterrupted way over a period of time. The idea of the relation of diversity is that of more than one distinct object existing at successive times, though “connected together by a close relation.” These two ideas are said to be “distinct,” in the sense that we can distinguish them from other ideas. The notion of diversity is said to be “perfect.” Despite the contrariness of these two ideas, we confuse them routinely in our common thinking. [The same explanation had been given in Section 2, paragraph 32, to account for our confusion of the relations of resemblance and identity as applied to perceptions, as opposed to the mind.] When the imagination contemplates an unchanging object, its action is very much like that when it reflects on successive but related objects. The two actions feel about the same, and the second action requires very little more effort than the first. “The relation facilitates the transition of the mind from one object to another, and renders its passage as smooth as if it contemplated one continu’d object.” The resemblance of these actions to each other causes the conflation of identity with diversity, ascribing identity, i.e., invariableness and uninterruptedness, to what is obviously a succession and hence diverse. We fall into it unawares and may try to correct ourselves by reflection, but philosophical thinking is too hard to sustain, in the face of the powerful bias of the imagination, to keep us from falling into the habit of confusing the two distinct ideas. In the end, we give up “and boldly assert that these different related objects are in effect the same, however interrupted and variable.” This “absurdity” is often justified by making up a “new and unintelligible principle, that connects the objects together, and prevents their interruption or variation.” In the present case, our perceptions are successive and distinct, but we disguise their variation with the notion of the soul, the self, and substance. In fact, in the case of plants and animals, to whom we do not attribute a soul, our bias toward identity is so great that we “are apt to imagine something unknown and mysterious, connecting the parts, beside their relation.”

[Footnote: The author offers as an example of a genius who is subject to this influence “by these seemingly trivial principles of the imagination“: Shaftesbury, in whose Moralists, a Philosophical Rhapsody, argues not only for the identity of plants and animals, but also for a principle uniting the whole universe.]

Even when we do not postulate an unknown unifying principle and do not find anything invariable or uninterrupted in a succession, we still have a propensity to consider it as an identity.

7. The dispute over identity is not merely verbal, as it involves the creation of a fiction, “either of something invariable and uninterrupted, or of something mysterious and inexplicable,” or a tendency to create a fiction. To prove that this is correct, the author will try to show how in daily experience, the objects that are distinct but deemed identical are in fact no more than successions related by resemblance, contiguity, or cause and effect. The relation of parts that leads to our fiction is only a quality that “produces an association of ideas, and an easy transition of the imagination from one to another.” And this quality is resemblance between two kinds of acts of the mind [as mentioned in paragraph 6 above]. The author will try to show how this accounts for why we attribute identity to distinct but related object. The author will then apply his explanation to personal identity, beginning in paragraph 15.

8. We begin by considering some mass of matter with contiguous parts. If we observe it for a while with no variation or interruption in its parts, we must attribute perfect identity to it. (The motion of the whole mass does not destroy this identity.) However, if even a single part, no matter how small or insignificant, is added to or removed from the mass, then strictly speaking it is not the same mass. It takes accurate thinking to recognize this, given the trivial character of the addition or subtraction, and we seldom think in such an accurate way. What accounts for our usual reluctance to declare identity destroyed is that “[t]he passage of thought from the object before the change to the object after it, is so smooth and easy, that we scarce perceive the transition, and are apt to imagine, that ’tis nothing but a continu’d survey of the same object.”

9. A “very remarkable circumstance” of this thought-experiment is that it is not the absolute size of the increase or diminution which influences the understanding, but only the relative size. The subtraction of a mountain would not affect our judgment of the identity of a planet, while a very tiny subtraction would be enough to lead us to pronounce very small objects to be different. This relativity is attributed to the fact that the smoothness of transition by the imagination is affected by the appearance of things: the earth would appear almost exactly the same (from a great distance) were a mountain to be removed.

10. The relativity in our judgments occurs not only with respect to the spatial components of objects, but it also has a temporal dimension. If the change occurs gradually and insensibly, we are likely not to take the object to be different before and after the change. The reason for this is the same: the transition from the earlier to the later state is not hindered by perceptible differences in the object. The continued perception is the basis for the attribution of continued existence to the object.

11. On the other hand, even if changes are imperceptible, at some point the change from the original may be great enough for us to give up our ascription of identity, unless it has some other foundation. And in fact, there is another basis for attributions of identity, “another artifice, by which we may induce the imagination to advance a step farther.” The new uniting principle is that of “the reference of the parts to each other, and a combination to some common end or purpose.” An example is that of a ship, many of whose parts have been replaced. The parts serve a common end, and the end persists even with the variation of the parts. This reference to a common end “affords an easy transition of the imagination from one situation of a body to another.”

12. In plants and animals, there is not only reference of the parts to a common end, but also a “sympathy” of the parts. That is, the parts enter into mutual relations of cause and effect in all their actions. This principle is so powerful that it influences us to judge a living thing to be identical even when all its matter and all the “figure of its parts” have changed. “An infant becomes a man, and is sometimes fat, sometimes lean, without any change in his identity.”

13. A final consideration is two phenomena, “which are remarkable in their kind.” The first of these is the confusion of numerical identity and specific identity [i.e., identity in kind]. Two examples are given. The first is a succession of distinct sounds that are deemed to be a single noise because they have a single cause. The second is the replacement of one church by another with a different structure and made of different materials. Here, it is the relation to the parishioners that leads to the identification. We call it the same church despite this variation because the two buildings do not co-exist, and hence the difference is not apparent at a single time, which eases the way for a judgment of identity.

14. The second phenomenon is that there is a tendency of the mind to attribute identity even when the change of its parts may be sudden, rather than gradual. If the nature of the object is to be subject to rapid change, we are, so to speak, more tolerant of a faster change than we would be ordinarily. A river is an example of this kind of object. Even if its parts are totally altered in the course of a day, we regard it as the same river. The explanation is that, “What is natural and essential to any thing is, in a manner expected; and what is expected makes less impression, and appears of less moment, than what is unusual and extraordinary.” Once again, if the appearance of difference is less notable when it is more common, there is less disruption in the transition of the imagination, which is the basis for our ascriptions of identity.

15. At this point, the author has concluded his observations and is ready to turn to the explanation of the attribution of identity to persons. He notes that personal identity has become a major issue of contention in England of late. As was hinted at in Section 5 above, the author applies to the case of personal identity the same explanation as was given for the previous cases in which there is sensible variation in the object. “The identity, which we ascribe to the mind of man, is only a fictitious one, and of a like kind with that which we ascribe to vegetables and animal bodies.” So the identity is to be attributed to “a like operation of the imagination upon like objects.”

16. The author finds the argument of the preceding paragraph convincing, but he offers another for those who remain unconvinced, reasoning that “is still closer and more immediate.” Any identity of the mind cannot remove the difference in the perceptions it has, as their difference is essential to them. [A yellow color is essentially different from a green one, for example.] Even in an identical mind, the perceptions are distinct, different, distinguishable, and separable from one another. The identical mind is supposed to unify the perceptions, but does it produce a relation between the perceptions themselves, or does it only associate them in the imagination? Is there a real bond, or do we merely feel a bond? We may answer these questions by invoking what has been previously concluded: “that the understanding never observes any real connexion among objects, and that the union of cause and effect, when strictly examin’d, resolves itself into a customary association of ideas.” [See Part III, Sections 6 and 14.] It follows from this that when on reflection we attribute unity to the perceptions, the connection among them can lie only in the imagination. The author has also claimed that there are only three principles that lead the mind to connect ideas: resemblance, contiguity, and causation. [For a brief discussion of this combination of relations, see paragraph 7 above. These three relations were originally introduced in Part I, Section 4 as associating qualities (or natural relations) that convey the mind from one idea to another.] “These are the uniting principles in the ideal world, and without them every distinct object is separable by the mind, and may be separately consider’d, and appears not to have any more connexion with any other object, than if disjoin’d by the greatest difference and remoteness.” Since these are the only uniting principles in the imagination, they are the ones that are responsible for attributions of identity. And because “the very essence of these relations consists in their producing an easy transition of ideas,” they are responsible for our idea of personal identity.

17. If resemblance, contiguity, and cause and effect are the only relations that could influence the imagination to pronounce diverse objects to be identical, which ones actually bring this about? Contiguity is immediately discounted as having “little or no influence in the present case,” which leaves resemblance and causation. [The reason that the relation of contiguity has little or no influence on the production of the idea of personal identity is that what is to be connected is successive perceptions. Thus, spatial contiguity plays no role at all and temporal contiguity would be the basis of ascribing identity only to two immediately succeding perceptions.]

18. The author approaches the role of resemblance in the attribution of personal identity from the perspective of an observer A [strictly, we], with the supposed ability to see clearly the succession of perceptions attributed to someone else, B. The succession itself is described by the author as constituting B’s mind or thinking principle. A further supposition is that B always preserves the memory of a considerable part of past perceptions. Memory naturally plays the key role here because a memory is an image of a past perception, and an image by its very nature necessarily resembles its original [or object]. Thus, in contemplating B’s perceptions, A places a considerable number of B’s resembling perceptions into B’s chain of thoughts. Then there is an easy transition in the imagination of A from one of these resembling perceptions to another, which leads A’s imagination to make the whole [succession of resembling perceptions] seem like the continuance of one object. The author notes that this mechanism applies to A’s ascription of personal identity to himself: The case is the same whether we consider ourselves or others. [A supposes that A can see clearly the succession of A’s own perceptions and that A remembers many of them and therefore finds them to be resembling. This resemblance eases the transition of A’s imagination from one perception to another to the point where A attributes an identity to himself.] The author concludes from this that, In this particular, then, the memory not only discovers the identity, but also contributes to its production, by producing the relation of resemblance among the perceptions. [Memory plays a dual role in the attribution of identity underlying a succession of perceptions. From the standpoint of the observer A, the role of B’s memory is to show B’s identity to A. (See paragraph 20 for the association of the word ‘show’ with ‘discover’ when it is contrasted with ‘produce’). From the standpoint of the observed B, without B’s memory, there would be insufficient resemblances among B’s perceptions to smooth the transition of the imagination of A from one perception to another. So memory produces an essential element in the attribution of the identity of B by A.]

19. The second key natural relation in the production of the idea of personal identity is causation. Here, the author proceeds by explaining the true idea of the human mind, the role of causation in that idea, and, in the next paragraph, the role of memory in applying causation to personal identity. The proper role of causation is to link our separately existing perceptions into a system whereby perceptions mutually produce, destroy, influence, and modify each other. Examples are the production of an idea from an impression and the production of an impression [of reflection, see Part I, Section 2]. More generally, “One thought chaces another, and draws after it a third, by which it is expell’d in its turn.” The author compares the mind to a state, with its relationships of governing and subordination. Just as a state remains even though its stock of citizens is constantly turning over, a person’s identity is said to be preserved even through changes in his dispositions and perceptions. The relation of causation still connects the perceptions that make up his parts. At this point, the author corroborates his account by applying it to the passions as opposed to the imagination. The passions make our temporally distant perceptions influence each other as well as giving us a concern in the present “for our past or future pains and pleasures.”

20. [The role of memory in the discovery and production of the idea of personal identity on the basis of the resemblance of perceptions was explained in paragraph 18.] At this point, the author states that the memory is the source of personal identity chiefly due to the fact that memory alone acquaints us with the continuance and extent of [an individual’s] succession of perceptions. Without this acquaintance, there would be no notion of causation, or consequently of that chain of causes and effects, which constitute our self or person. However, after we get the notion of causation, we can extend the connections of perceptions beyond our memory, and can comprehend times, and circumstances, and actions, which we have entirely forgot. Thus, we attribute continued existence of our identical self to times about which we have entirely forgotten what happened. [Unlike the case of resemblance,] in this view, therefore, memory does not so much produce as discover personal identity, by showing us the relation of cause and effect among our different perceptions. [In the case of resemblance, memory actually produces resembling perceptions, but as the author has noted, at times memory cannot fill in the gaps in our perceptions and hence does not produce our idea of the identity of the person. However, it discovers that relation indirectly by providing the basis for those causal connections that allow us to suppose our continued existence over times that we cannot remember.] The author concludes the paragraph by noting that the fact that memory does not entirely produce the idea of personal identity imposes a burden of proof upon those who claim that it does. How, the author asks, can such a view explain why we can thus extend our identity beyond our memory. [The apparent target here is Locke, who claimed that as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person (An Essay concerning Human Understanding, Book II, Chapter 27, paragraph 9). The author’s point is that we often cannot extend our consciousness backward to some thoughts, yet because of causal relations between our thoughts, we attribute identity nonetheless. Locke might respond that in the sense of ‘can’ that he is using, incidents which we have entirely forgot might be recollected under favorable circumstances. At one point, Locke denies personal identity to a consciousness which is wholly stripped of all the consciousness of its past existence, and lose[s] it beyond the power of ever retrieving it again: and so as it were beginning a new account from a new period [would] have a consciousness that cannot reach beyond this new state (An Essay concerning Human Understanding, Book II, Chapter 27, paragraph 14). The precise meaning of Locke’s account of personal identity remains controversial to this day.]

21. This account of identity has the momentous consequence that the extant disputes about personal identity cannot be resolved, and that they are only verbal. An example of such a dispute is differing claims about how much change in an object can take place before the object ceases to be the same thing. According to the author’s explanation, there is no “just standard” to decide the issue, because the sources of the idea of identity, the relations of resemblance and causality, and the smoothness of the transition in the imagination, “may diminish by insensible degrees.” [We might now say that because of the source of the judgment of identity, there is an inherent vagueness in the concept.] The only disputes about identity that are not merely verbal are those which concern the relations that give rise to the fiction of union, [such as commonality of purpose or sympathy of parts].

22. It may be recalled that a second quality attributed to the human mind, besides identity over time, is simplicity at a given time. The author proposes to apply the same reasoning to both cases. If the parts of an object are bound together by a close relation, the feeling is nearly the same as when there is a simple and indivisible object, “and requires not a much greater stretch of thought in order to its conception.” Because of the resemblance between the feelings resulting from observing a simple and a closely-related complex object, we “feign a principle of union” to account for the simplicity that we attribute to the complex object. This principle is supposed to be “the support of this simplicity, and the center of all the different parts and qualities of the object.”

23. This account of the alleged identity and simplicity of the soul concludes the examination of systems of philosophy regarding the natural world [the ancient and modern systems examined in Sections 3 and 4], as well as the internal world of the mind [the systems of the immateriality and of the identity and simplicity of the soul, as viewed in Section 5 and the present section]. The varied observations made in the course of these sections shed light on the author’s own system as presented in the first three Parts of Book I as well as pave the way for his system of the passions in Book II. The author will turn to this subject to complete “the accurate anatomy of human nature.”

The Appendix

After recounting his argument for the claim that we have no notion of the mind apart from particular perceptions, the author finds himself at a loss to explain how those perceptions are connected. “I am sensible, that my account is very defective, and that nothing but the seeming evidence of the precedent reasonings cou’d have induc’d me to receive it.” The problem is that we cannot discover connections, but only feel a determination of thought to pass from one object to another. Thus, the mind arrives at an idea of personal identity only by reflecting on its past train of perceptions and feeling them to be connected and naturally introduced as they occur. This is in conformity with the view of most philosophers that personal identity “arises from consciousness; and consciousness is nothing but a reflected thought or perception.” This gives some promise for the author’s view, but this promise vanishes because he cannot find a satisfactory theory to explain the principles that “unite our successive perceptions in our thought or consciousness.” The author ends by stating that “there are two principles, which I cannot render consistent; nor is it in my power to renounce either of them . . . .”

• Every distinct perception we have is a distinct existence,
• The mind never perceives a real connection between distinct existences.

The “Abstract”

The author’s description of his own account of the human understanding (“the logics of this author”) concludes with two opinions, “which seem to be peculiar to himself, as indeed are most of his opinions.” The first of these is the conception of the soul as “nothing but a system or train of different perceptions, those of heat and cold, love and anger, thoughts and sensations; all united together, but without any perfect simplicity or identity.” He understands Descartes as having held that the essence of the mind is “thought in general.” But this could not be right, as all existing things are particulars. The author concludes from this that the particular perceptions “compose” the mind, rather than belonging to it. The reason is that the notion of a substance in which perceptions inhere is unintelligible. [See Book I, Part IV, Section 5 for a general discussion of this point.] We have no idea of such a substance because there is no impression, spiritual or material, of which it is a copy. Our ideas of bodies are composed of particular perceptions, such as tastes, colors, shapes, etc, and so “our idea of any mind is only that of particular perceptions, without the notion of any thing we call substance, either simple or compound.”

The Enquiry

The topic of personal identity is not raised in the Enquiry.

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