Locke on Personal Identity Shelley Weinberg Philosophy Compass, vol. 6 (June, 2011) Locke's account of personal identity has been highly influential because of its emphasis on a psychological criterion. The same consciousness is required for being the same person. It is not so clear, however, exactly what Locke meant by 'consciousness' or by 'having the same consciousness'. Interpretations vary: consciousness is seen as identical to memory, as identical to a first personal appropriation of mental states, and as identical to a first personal distinctive experience of the qualitative features of one's own thinking. There is wide agreement, however, that Locke's theory of personal identity is meant to complement his moral and theological commitments to a system of divine punishment and reward in an afterlife. But these commitments seem to require also a metaphysical criterion, and Locke is insistent that it cannot be substance. The difficulty reconciling the psychological and metaphysical requirements of the theory has led, at worst, to charges of incoherence and, at best, to a slew of interpretations, none of which is widely accepted. Locke's theory of personal identity was revolutionary in its own time and remains of interest today because it was the first to include a non-substantial account of personal identity. Locke states, "For the same consciousness being preserv'd, whether in the same or different Substances, the personal Identity is preserv'd" (II.xxvii.13).1 Being the same person is to have the same consciousness. Many have interpreted Locke to mean by 'consciousness' either having the same memories2 or having one or more mental states by which the one who is aware of those mental states as her own can identify herself as a previous person.3 Therefore, consciousness is thought to be a purely psychological criterion. Locke also seems to see his theory of personal identity as complementing his moral and theological views.4 "Person", Locke says, "is a Forensick Term appropriating Actions and their Merit", for which "at the Great Day" we are judged by God and receive eternal reward or punishment (II.xxvii.26, I.iv.5). But for a just determination of eternal deserts ("divine 2 rectification") it seems that whatever accounts for the identity of the person must have some sort of continued existence that can be known objectively by God. After all, we don't remember all that we do. Of course, God can restore to me the appropriate memories. But, then, God must be looking to something other than my own first personal awareness of what I have done to determine which memories truly belong to me. Therefore, what is missing from a purely psychological account of personal identity is something to consult from a third personal point of view to ensure that I get exactly the reward and punishment I deserve. Thus, there arises an inherent tension in Locke's account: a psychological criterion for personal identity does not appear sufficiently metaphysically robust for the work required in divine rectification. Increasing the difficulty, Locke adamantly denies that the continuing existence of substance can to do the necessary work. Although the scholarship is voluminous, a single widely accepted interpretation that reconciles these apparently conflicting commitments has yet to emerge. In what follows, I first address some of the historical development of the scholarship attributing to Locke a psychological theory of personal identity, noting various problems and attempted solutions. I then draw attention to the current difficulty reconciling any purely psychological interpretation with Locke's apparent need also for an objective criterion. I then briefly outline a possible, textually supported route out of the difficulty. Consciousness as a Psychological Criterion for Identity Locke's theory of personal identity, found in Book II, chapter xxvii (Of Identity and Diversity) was added to the second edition of the Essay concerning Human Understanding, at the urging of William Molyneaux, one of Locke's trusted interlocutors and correspondents. In 3 this chapter, Locke is concerned to show through a series of thought experiments why we should see consciousness rather than substance as the criterion for personal identity. For example, in II.xxvii.14, Locke considers whether having the same soul (i.e., immaterial thinking substance as distinguished from consciousness) is sufficient for being the same person: Let any one reflect upon himself, and conclude, that has in himself an immaterial Spirit, which is that which thinks in him, and in the constant change of his Body, keeps him the same; and is that which he calls himself: Let him also suppose it to be the same Soul that was in Nestor or Thersites, at the Siege of Troy, ...which it may have been, as well as it is now, the Soul of any other Man: But he, now having no consciousness of any of the Actions of either Nestor or Thersites, does, or can he, conceive himself the same Person with either of them? Can he be concerned in either of their Actions? Attribute them to himself, or think them his own more than the Actions of any other Man, that ever existed? And in II.xxvii.23 Locke considers the case of ...two distinct consciousnesses acting [in] the same Body, the one constantly by Day, the other by Night; and on the other side the same consciousness acting by intervals two distinct Bodies: I ask in the first case, Whether the Day and the Night-man would not be two distinct Persons, as Socrates and Plato; and in the second case, there would not be one Person in two distinct Bodies, as much as one Man is the same in two distinct clothings. In these two examples, Locke wants us to think about what makes a person identical through time. In the first case, we see that consciousness rather than substance is the criterion for personal identity. That we can conceive of ourselves as the same self allows us to make sense of the concern we have for our own past actions, and this first personal relation to ourselves is of primary importance when it comes to personal identity. In the second case, Locke is pointing out that were different consciousnesses able to travel between different substances (in this case bodies, but just as easily minds or souls),5 we would identify the person with the consciousness and not with the body (or mind), just as we identify the same man despite the different clothes he wears on different occasions. 4 What, though, does Locke mean by 'consciousness', and how does it serve as the criterion for personal identity? To answer this question it is helpful first to consider his view of what constitutes a person: This being premised to find wherein personal Identity consists, we must consider what Person stands for; which, I think, is a thinking intelligent Being, that has reason and reflection, and can consider it self as it self, the same thinking thing in different times and places, which is does only by that consciousness, which is inseparable from thinking, and as it seems to me essential to it: It being impossible for any one to perceive, without perceiving, that he does perceive. (II.xxvii.9) It is important that the features necessary for personhood are not all considered as necessary for personal identity. So, even though, say, reflection and rationality are required in order to be a person, one need not have the same faculty of reflection to be the same person. That is, one need not be the same thinking substance to be the same person. One need only have the same consciousness. So already in the definition of 'person' we have a distinction drawn between thinking (or reflecting) and consciousness. Moreover, Locke tells us that consciousness is "inseparable from thinking, and as it seems essential to it", which implies that although not the same thing, thinking and consciousness are very closely linked.6 I think it is also safe to say that Locke intends consciousness to include self-consciousness: in every perception I am aware that I am the one perceiving. Locke then adds an important condition: ...as far as this consciousness can be extended backwards to any past Action or Thought, so far reaches the Identity of that Person; it is the same self now it was then; and 'tis by the same self with this present one that now reflects on it, that that Action was done. (II.xxvii.9) Only insofar as we are aware of ourselves as stretching into the past are we the same self or person.7 This is followed by the claim that knowing that we are identical to a past self is achieved by reflecting on a past thought or action. Early on, quite a lot of emphasis was placed on Locke's claim above that a person is identical to herself as far as her consciousness can be extended to a past action. That is, the criterion for 5 personal identity (consciousness) was thought to be identical to what we can know about our own continuity through time. This in combination with Locke's explicit assertion that it "matters not at all...whether it be the same Identical Substance, which always thinks in the same Person" (II.xxvii.10) led some to argue that the criterion for personal identity is simply memory.8 A present person is identical to a past one only insofar as she remembers or it is possible for her to remember herself thinking and acting in the past. But as soon as Locke was attributed with a simple memory theory, there followed devastating criticism. Two historically prominent objections were lodged in the eighteenth century, one by Thomas Reid and the other by Samuel Butler. Reid argued that if being the same person is simply having the same memories, then personal identity fails the logic of transitivity.9 Consider Reid's famous example: Suppose a brave officer to have been flogged when a boy at school, for robbing an orchard, to have taken a standard from the enemy in his first campaign, and to have made a general in advanced life: Suppose also, which must be admitted to be possible, that when he took the standard, he was conscious of his having been flogged at school, and that when he made a general he was conscious of his taking the standard, but had absolutely lost the consciousness of his flogging. (376) Reid's point is that construing Locke's theory as a simple memory theory allows that the officer would remember the flogging and therefore be the same person as the boy, and the general would remember taking the standard from the enemy and so be the same person as the officer, but the general, because he has no memory of the flogging would not be the same person as the boy. Although thought to be devastating to Locke's theory for many years, in the early 1950's there came a solution to the transitivity problem.10 We need not remember every action of a past self to be identical to that self. Rather, we can establish identity with an unremembered self through an intermediate self (an ancestor) that we do remember. So, the brave officer, who remembers the flogging as a child and who is remembered by the general, serves as the ancestral 6 link between the general and the child. Personal identity is preserved even though the general has no memory of the child's flogging. Nevertheless, preserving transitivity does not get Locke's theory completely out of the woods, for there is the famous criticism of circularity lodged by Butler in The Analogy of Religion in 1736. As Butler puts it, "Anyone should really think it self-evident, that consciousness of personal identity presupposes, and therefore cannot constitute, personal identity, any more than knowledge, in any other case, can constitute truth, which it presupposes" (I:385). This objection is devastating for any kind of memory theory that is also taken to be a metaphysical theory. The problem is that an epistemic criterion for personal identity (what we can know or remember of a past self) must already be presupposing an identical self to know. That is, there is no noncircular criterion for distinguishing the representation of a past state that is an accurate memory from a representation of a past state that is a delusion or a false memory. So, either there is no truth to ground the knowledge claim that I am the same person or the account commits circularity. One strategy to solve the circularity problem is simply to embrace the epistemic constitution of the self and jettison any commitment to a metaphysical understanding of what constitutes the identity of a person. These interpretations see Locke as having what may be called an "appropriation theory" of personal identity.11 That is, my self is constituted solely epistemically by whatever thoughts and actions I can presently attribute to myself, or call my own. Moreover, my present self is identical to a past self if I can be linked by memory through a series of ancestor selves. Passages considered key to supporting this interpretation include Locke's use of the terms 'appropriation' (II.xxvii.16), 'self-attribution' (II.xxvii.17, 18), or the 'imputing' (II.xxvii.18) of actions to oneself. Kenneth Winkler, whose appropriation theory interpretation 7 of Locke has been highly influential, considers the following to be the most "powerful evidence" supporting his proposal: Person, as I take it, is the name for this self. Where-ever a man finds, what he calls himself, there I think another may say is the same Person...This personality extends it self beyond present Existence to what is past, only by consciousness, whereby it becomes concerned and accountable, owns and imputes to it self past Actions, just upon the same ground, and for the same reason, that it does the present...And therefore whatever past Actions it cannot reconcile or appropriate to that present self by consciousness, it can no more be concerned in, than if they had never been done. (II.xxvii.26) The focus is on the way in which the appropriation or self-imputation of thoughts and actions constitutes the extension of "personality" through time. Although Winkler interprets Locke as saying that the self has a "certain authority over its own constitution" (154), we need not worry that the self can be strategically constructed to avoid just deserts, since whatever I take myself to include is what my consciousness "reveals to me" as mine in any particular moment. Appropriation theories, in privileging the psychological and epistemic aspect of personal identity, however, suffer when it comes to meeting the metaphysical requirements of the theory. There doesn't seem to be enough of an objective criterion for divine rectification, since we all have gaps in memory that make it difficult to link a present self by appropriation to all of our past selves. So, there very well may be a past action that deserves punishment that cannot be subjectively appropriated in consciousness. Moreover, given the possibility of false memory, I can be held responsible for things I never did (II.xxvii13). Although this may not be a devastating problem in civil courts of law where the assessment of just desert is not expected to be perfect, it is devastating for a system of divine justice that is supposed to correct for human error. Another way to interpret Locke's understanding of consciousness as a psychological criterion is to see it not simply as memory or appropriation of mental states, but as the distinct internal 8 experience of the unity of one's own thinking. Margaret Atherton argues that persons are individuated by their consciousness and that there can be a "unity of consciousness" that is different from the "integrative unity" of thinking. That is, we experience a "distinct internality" to thinking (internally distinct and idiosyncratic qualitative features) that is not identical to those mechanisms causally responsible for having thinking at all (288). Thus, the unity of consciousness is the awareness of mental states as the seeing of red, as the tasting of wine, and as mine. Although Atherton's interpretation is instructive for seeing consciousness as more than and distinct from thinking, the problem it shares with all theories that interpret consciousness as psychological is the lack of something sufficiently metaphysical (that is also not substance) to ground Locke's commitment to divine rectification. Consciousness as a Metaphysical Criterion Is there anything in Locke's account that is sufficiently metaphysical? Answering this question has led a number of scholars to focus attention on what Locke says about the continued existence of other kinds of things.12 We find this particular discussion in Locke's II.xxvii.2-7 analogy between the identity condition for persons and the identity conditions for atoms, masses of matter, plants, animals, and human beings. Locke begins with what individuates a particular thing of any kind. According to Locke, an individual thing begins to exist at a particular time and place (II.xxvii.1). It continues to exist as that thing insofar as the criterion for the identity of its kind is satisfied. But how does Locke determine the identity conditions for any particular kind? Departing from a Cartesian understanding of the identity of things, Locke says, 'Tis not therefore the Unity of Substance that comprehends all sorts of Identity, or will determine it in every Case: But to conceive, and judge of it aright, we must consider what the Idea the Word it is applied to stands for: It being one thing to be the same Substance, another the same Man, and a third the same Person, if Person, Man, and Substance, are three Names standing for 9 the three different Ideas; for such as is the Idea belonging to that Name, such must be the Identity. (II.xvii.7) What must continue to exist for something to qualify as the same thing through time depends on what kind of thing we're talking about, namely what satisfies our idea of that thing.13 An atom, for example, is identical to itself as long as it is "a continued body under one immutable Superficies, existing in a determined time and place" (II.xxvii.3). That is, an atom endures as the same atom as long as its surface properties do not change. A mass of matter continues to exist as the same mass of matter as long as the atoms composing it do not change. Once we get to living things, however, it gets more complicated. Surely, we don't want to say that an oak tree is not identical to itself if it loses a leaf, nor do we want to say that I am not the same human being as I shed my skin cells. How, then, we should ask ourselves, are oak trees and human beings different from masses of matter? In brief, masses of matter are simply collections of particles, whereas the collections of particles that are plants, animals, and human beings also have a disposition, in virtue of their organization, to sustain life: ...an oak differs from a Mass of Matter...[in] that the one is only the Cohesion of Particles of Matter any how united, the other such a disposition of them as constitutes the parts of an Oak; and such Organization of those parts, as is fit to receive, and distribute nourishment, so as to continue, and frame the Wood, Bark, Leaves, etc. of an Oak, in which consists the vegetable Life. (II.xvii.4) If we combine the criterion for individuation with the criterion for the continued existence of a living thing, we can say the following: a particular living thing begins to exist when its life begins, and it continues to exist as that thing it is as long as its life continues. Locke says, "This shows wherein the same Man [human being] consists; viz. in nothing but the participation of the same continued Life, by constantly fleeting Particles of Matter, in succession vitally united to the same organized body" (II.xxvii.6). How else, Locke queries, can we say that I am the same human being as the infant born to my parents, without also making it possible that I am the same 10 human being as Marie Antoinenette or Ghandi? So, the continued existence of a single human being is commensurate with the duration of her life. Locke then explains that the identity condition for persons works the same way: The Question being what makes the same Person, and not whether it be the same Identical substance, which always thinks in the same Person, which in this case matters not at all. Different Substances, by the same consciousness (where they so partake in it) being united into one Person; as well as different Bodies, by the same Life are united into one Animal, whose Identity is preserved, in that change of Substances, by the unity of one continued Life. (II.xxvii.10) The same continuing consciousness makes the same person, despite fleeting changes in substance, whether bodily, due to changes in particles, or mental, due to changes in thoughts, just as the same continuing life makes the same plant, animal, or human being. Although the analogy is not strict in that the life of a plant just is the organization of parts where consciousness is something more than the organization or unity of thinking,14 the point is that both life and consciousness are something distinct from the fleeting things in which they participate. And like the life of a plant, animal or human being, Locke seems to think that consciousness persists through our momentary psychological states of ourselves as thinking and acting. Most of the interpretations that focus on the analogy of consciousness to life, however, stop short of assigning Locke the view that there is a metaphysical fact of a continuing consciousness that is not reducible to substance.15 But these stop short of finding what Locke needs for divine rectification: an objectively continuing consciousness that does not appeal to substance to ground its continuity. There is, however, one interpretation that finds textual support for just such a criterion.16 Perhaps the most telling piece of evidence that Locke considered consciousness as having a continued existence is in II.xxvii.25 where he asserts that consciousness has "duration": 11 This every intelligent Being, sensible of Happiness or Misery, must grant, that there is something that is himself, that he is concerned for, and would have happy; that this self has existed in a continued Duration more than one instant, and therefore, 'tis possible may exist, as it has Done, Months and Years to come, without any certain bounds to be set to its duration; and may be the same self, by the same consciousness, continued on for the future. And thus, by this consciousness, he finds himself to be the same self which did such or such an Action some Years since, by which he comes to be happy or miserable now. In all which account of self, the same numerical Substance is not considered, as making the same self: But the same continued consciousness, in which several Substances may have been united, and again separated from it, which whilst they continued in a vital union with that, wherein this consciousness then resided, made a part of that same self. (II.xvii.25, my emphasis in boldface) Although Locke more frequently speaks of consciousness as a momentary psychological state of awareness of myself as thinking and acting or remembering or appropriating my thoughts and actions, here Locke says that consciousness has "duration", which, for him, is a technical term standing for the "distance between...the appearance of any two Ideas in our Minds" (II.xiv.3). Moreover, in II.xiv, Locke uses the term 'duration' as a synonym for 'continued existence'. He says, "we call the Existence, or the Continuation of the Existence of our selves, or anything else, Commensurate to the succession of any Ideas in our Minds, the Duration of our selves, or any such other thing co-existing with our Thinking" (II.xiv.3). And even though a single thought takes up the time of only an instant and so we can have only a momentary idea of our own duration or of the duration of any other thing, Locke seems to be saying that things endure objectively through our successive perceptions of ideas of them. If consciousness has duration, then Locke must be thinking that it too continues to exist through any gaps in our subjective conscious states. Locke continues that although we cannot know the actual duration, or distance, between any two perceptions of ideas, we get an idea of the length of that duration by using the ideas we have as marks for measurement. As Locke says, "Duration in it self is to be considered, as going on in one constant, equal, uniform Course: but none of the measures of it, which we make use of, can 12 be known to do so" (II.xiv.21). Nevertheless, God can know the continued existence of things as they persist through those ideas by which we are able to measure their duration. Locke says, "God's infinite Duration being accompanied with infinite Knowledge, and infinite Power, he sees all things past and to come; and they are no more distant from his Knowledge, no farther removed from his sight, than the present" (II.xv.12). So, even though we cannot perceive the actual duration of things through the gaps in our awareness, say, while we are dreamlessly sleeping, the full extent of our duration is known by God. Thus, Locke seems to think consciousness continues to exist in some sort of objective metaphysical way. What, then, do we do with all those passages in which Locke seems to equate consciousness with a state of awareness of our mental states or of an internal experience of the unity of our own thinking? That there are passages leading to both psychological and metaphysical interpretations of consciousness suggests that Locke is using the term 'consciousness' ambiguously. He seems to see consciousness as 1.) a mental state inseparable from an act of perception by means of which we are aware of ourselves as perceiving. This is the sense of consciousness in those passages emphasized in the "memory" and "appropriation theory" interpretations, as well as in those that see consciousness as an internally distinct experience of my own thinking. But Locke also seems to see consciousness as 2.) the ongoing self we are aware of in these conscious states. The second sense is the objective fact of an ongoing consciousness, something that is epistemically available from a third personal (maybe only God's) point of view. The ongoing self that I am aware of in being conscious of past and present thoughts and actions seems also to have an objective continued temporal existence (duration) through any gaps in my successive states of awareness of myself.17 For example, Locke sometimes speaks of consciousness not only as a distinct thing, but also as something that continues through time. He 13 talks about there being "two distinct incommunicable consciousnesses" alternating by day and night (II.xxvii.23), "the same consciousness being transferr'd from one thinking Substance to another" (II.xxvii.13), "the same consciousness being continued in a succession of several Substances" (II.xxvii.10), and in several places, the "same consciousness extended" (II.xxvii.9, 10, 16), "reaching" (II.xxvii.9, 17), and "continued" (II.xxvii.25) into the past or future. Nevertheless, even if we grant that Locke considered consciousness to be something objectively enduring, how would it fit into Locke's ontology? It cannot be a substance and it seems ill suited to be a mode, since modes are either mental constructions or reducible to substance.18 Locke does seem to give us a clue. Just prior to the II.xxvii.25 passage in which Locke identifies consciousness as having duration, he considers which ontological category might be best fitted to consciousness. He says, "I agree the more probable Opinion is, that this consciousness is annexed to, and the Affection of one individual immaterial Substance." Locke then continues in this vein: "But let Men according to their divers Hypotheses resolve that as they please. This every intelligent Being, sensible of Happiness or Misery, must grant, that there is something that is himself, that he is concerned for, and would have happy;" (II.xxvii.25). Perhaps we can take Locke to be saying something like the following. Indeed, most who think about ontological categories accept the traditional Cartesian schema of substances and modes of substances. Confined to this taxonomy, most would probably classify consciousness as a mode (affection) of a thinking substance. But Locke himself need not be seen as necessarily sharing that opinion. First, it is uncontroversial that Locke views classification as not mapping what nature inherently has to offer, but rather as arising from the content of our ideas from experience. So, it is reasonable that Locke is more interested in providing an analysis of what we experience than remaining faithful to the Cartesian ontology he inherited.19 If we acknowledge that Locke is 14 stretching the boundaries of traditional metaphysical classification, then perhaps we can allow him both the psychological and the metaphysical aspects of consciousness he needs for a coherent theory of personal identity.20 15 Works Cited Aaron, Richard I. John Locke. Oxford: Oxford University Press, 1971. Allison, Henry E. "Locke's Theory of Personal Identity: A Re-Examination." Journal of the History of Ideas 27 (1966): 41-58. Alston, William and Bennett, Jonathan. "Locke on People and Substances." The Philosophical Review 97 (1988): 25-46. Atherton, Margaret. "Locke's Theory of Personal Identity." Midwest Studies in Philosophy 8 (1983): 273-94. Ayers, Michael. Locke, Vol. II. London and New York: Routledge, 1991. Behan, David. "Locke on Persons and Personal Identity." Canadian Journal of Philosophy IX (1979): 53-75. Berkeley, George. Alciphron in The Works of George Berkeley. Ed. T. E. Jessop and A. A. Luce, 9 Vols. London: Thomas Nelson and Sons. Vol. 3, 1948. Bolton, Martha Brandt. "Locke on Identity: The Scheme of Simple and Compound Things." Individuation and Identity in Early Modern Philosophy. Eds. K. F. Barber and J. J. E. Gracia. Albany: State University of New York Press, 1994. Butler, Joseph. The Works of Joseph Butler. Ed. W. E. Gladstone. Oxford: Oxford University Press. Vol. I, 1986. Chappell, Vere. "Locke and Relative Identity." History of Philosophy Quarterly 6 (1989): 69-83. Coventry, Angela and Kriegel, Uriah. "Locke on Consciousness," History of Philosophy Quarterly 25 (2008): 221-42. Curley, Edwin. "Leibniz and Locke on Personal Identity." Ed. M. Hooker, Leibniz: Critical and Interpretive Essays. Minneapolis: University of Minnesota Press, 1982. Flew, Anthony. "Locke on Personal Identity." Philosophy 26 (1951): 53-68. Ed. John Perry. Personal Identity. Berkeley, Los Angeles, and London: University of California Press, 1975. Geach, P. T. "Identity," Review of Metaphysics 21 (1967-68): 3-12. Grice, H. P. "Personal Identity." Mind 50 (1941). Ed. John Perry. Personal Identity. Berkeley, Los Angeles, and London: University of California Press, 1975. 16 Jolley, Nicholas. Locke: his philosophical thought. Oxford: Oxford University Press, 1999. Langtry, Bruce. "Locke and the Relativisation of Identity," Philosophical Studies 27 (1975): 401-09. Locke, John. An Essay concerning Human Understanding, 4th Edition. Ed. P.H. Nidditch. Oxford: Clarendon Press, 1975. Mackie, J. L. Problems From Locke. Oxford: Clarendon Press, 1976. Mabbott, J. D. John Locke. London and Basingstoke: The Macmillan Press Ltd, 1973. McCann, Edwin. "Locke on Identity: Matter, Life, and Consciousness." Archive fur Geschichte der Philosophie 69 (1987): 54-77. Ed. M. Atherton. The Empiricist: Critical Essays. Rowan and Littlefield, Lanham MD, 1999. Noonan, Harold. "Locke on Personal Identity." Philosophy 53 (1978). Quinton, Anthony. "The Soul and Spiritual Substance." The Journal of Philosophy 59 (1962). Ed. John Perry. Personal Identity. Berkeley, Los Angeles, and London: University of California Press, 1975. Reid, Thomas. Essays on the Intellectual Powers of Man. Ed. Derek Brookes. University Park: Pennsylvania State University Press, 2002. Uzgalis, William L. "Relative Identity and Locke's Principle of Individuation." History of Philosophy Quarterly 7 (1990): 283-97. Weinberg, Shelley. "The Coherence of Consciousness in Locke's Essay." History of Philosophy Quarterly 25 (2008): 21-39. _____. "The Metaphysical Fact of Consciousness in Locke's Theory of Personal Identity." Journal of the History of Philosophy (forthcoming). Winkler, Kenneth. "Locke on Personal Identity." Locke. Ed. Vere Chappell. Oxford: Oxford University Press, 1998. Yaffe, Gideon. "Locke on Ideas of Identity and Diversity." The Cambridge Companion to Locke's Essay. Ed. Lex Newman. Cambridge: Cambridge University Press, 2007. 17 1 All references to Locke's Essay concerning Human Understanding appear in the body of the paper by book number.chapter number.section number. 2 Allison (1966), Flew (1975), Mabbott (1973). 3 Aaron (1971), Jolley (1999), Mackie (1976), Winkler (1998). 4 Alston and Bennett (1988), Ayers (1991), Jolley (1999), McCann (1999), Uzgalis (1990), Winkler (1998), Yaffe (2007). 5 Remember that Locke is officially agnostic about whether matter can think (IV.iii.6). 6 See Weinberg (2008) and Coventry and Kriegel (2008) for views that consciousness is a mental state inseparable from an act of thinking that is neither identical to reflection nor identical to ordinary perception. 7 I follow most Locke scholarship by treating 'self' and 'person' as synonymous. 8 Berkeley (1948), Butler (1986), Reid (2002), Flew (1975), Mabbott (1973). 9 Reid's objection originated with George Berkeley (1948:299). 10 See Grice (1975) and Quinton (1975). 11 Behan (1979), Curley (1982), Mackie (1976), Winkler (1998). 12 Alston and Bennett (1988), Atherton (1983), Ayers (1991), McCann (1999), Uzgalis (1990). 13 This has led some (Geach, 1967-8; Langtry, 1975; Mackie, 1976; Noonan, 1978) to interpret Locke as having, in differing degrees, a relative theory of identity. Chappell (1989), Alston and Bennett (1988), and Uzgalis (1990) argue against this view. 14 Atherton (1983:288) gives two reasons why what she calls the "integrative unity" of thinking is "not the same as the unity of consciousness": first, that we can imagine some "underlying cause" of the unity of our thoughts and ideas that allowed for two distinct consciousnesses, and second, that given his arguments against Descartes, Locke would not want to say that we know that what provides an essential integrative unity to our "thoughts, desires, and powers to move" is conscious thought. 15 For example, Alston and Bennett (1988:145, note 14) say it could be 'person-stages', 'person-at-a-time stages', or 'thinking substances-at-times'. 16 Weinberg (forthcoming). 17 We see intimations of this view also in Aaron (1971:152-53), Bolton (1994:116), and Mackie (1976:178). 18 Uzgalis (1990) argues that consciousness is a mixed mode, and Yaffe (2007) argues that the objective fact necessary for divine rectification is a moral fact rather than a metaphysical fact. 19 Alston and Bennett (1988:45, note 14) and Winkler (1998:165-68) acknowledge that Locke seems to be employing an ontology that requires more explanation. 20 Many thanks to Mary Domski and Helga Varden.