论文代写Locke’s Personal Identity Theory
The question about personal identity concerns the requirements for an individual to remain identical through time and change. This kind of identity is the diachronic identity of person. The question of personal identity also involves the question of how an individual can be distinguished from other individuals and so be individuated. This paper will address Locke’s theory of personal identity and focus on the diachronic identity because it is what Locke is interested in. Section 2 deals with Locke’s relativity of identity thesis and his theory of personal identity. In section 3, I will defend Locke from two objections: the objection from false memory, and the objection from circularity. In section 4, I will make a brief comparison between Locke’s view on personal identity and Descartes’s.
Relativity of Identity and Personal Identity
In his Essays, Locke develops a subtle theory of personal identity. I think the most important component of this theory is in his relativity of identity thesis. The main idea behind this thesis is that different ideas convey different identity criteria. When we try to make sense of the identity of something, there are issues pertaining to the concepts that are applied to whatever’s identity is in question. So, in order to make sense of personal identity, the first thing is to investigate what the concept “person” stands for. After clarifying the concept, we go on to investigate the identity criterion of this concept, namely ,the concept of person. Locke puts this point clearly in the following passage:
[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 three different ideas; for such as is the idea belonging to that name, such must be the identity…. (p. 137)
Also, for the same thing, we may apply different concepts to this thing. Consider a bronze bust of Beethoven. There is, obviously, a sculpture and a quantity of bronze. One might raise a question: is the sculpture the very same thing as the bronze? Descartes might reply “Yes.” Just like his wax, this piece of sculpture can be melted down and shaped into a cube; however, the identity of the thing in question, say, the bronze bust of Beethoven, remains identical. This is counterintuitive to laypersons and most current philosophers. Although the bust and the bronze share the same material and have physical properties in common, they differ in their identity condition. For a quantity of bronze, even if it is melted down and reshaped, it remains the same. For a bust of Beethoven, it ceases to exist if it is no longer a sculpture.
In the case of personal identity, we use “Spirit,” “Man,” and “Person” to denote to the same thing, each of which has different sense, and so has different identity criteria. It follows, for Locke, there might be different answers to the question—how an individual being remains identical through time and change—depending on which concepts we apply. Locke notes, “If it be possible for the same Man to have distinct incommunicable consciousness at different times, it is past doubt the same Man would at different times make different Persons” (p. 144). It suggests that X (the individual at t1) might be diachronically identical with Y (the individual at t2) with respect to the notion of man, while X and Y are by no means identical with respect to the notion of person.
So far, so good. But one may raise a question: Can Locke successfully distinguish [the concept of] person both from man and spirit? Locke needs to establish the conceptual distinction among the three concepts and so he has to prove that the concept of person is independent of the concept of man and that of spirit, and thus that person is sui generis concept, whose independence can be secured. In fact, Locke gives four thought experiments to establish the conceptual independence of person. These four thought experiments are similar because they have the same pattern of reasoning. That is, they all start from the conceivability to the genuine metaphysical possibility; e.g., the conceivability that X and Y have the same spirit but are different persons entails the possibility that X and Y are spiritually identical but personally discernible. Because it is hard to exclude the possibilities that personal identity is dissociated with the identity of man and the identity of spirit, it is better to separate the concept of person from the other two concepts.
Now, we turn to Locke’s account of personal identity. In book II, he argues that “it is consciousness … which makes the same person and constitutes the inseparable self.” This passage suggests that the personal identity consists in the consciousness that an individual has. This means X and Y are identical with regard to the notion of person if and only if X and Y share the same consciousness. But what is consciousness according to Locke?
Some identify consciousness with memory. This is a natural interpretation of consciousness, since Locke seems to identify a consciousness with “a present representation of past action” (p. 140). He also states that “to remember is to perceive anything with memory, or which a consciousness, that it was known or perceived before” (p. 144). Recently, some scholars reject this interpretation of Locke’s consciousness. Samuel Rickless, for instance, distinguishes actual memory from potential memory. It is possible that X (a person at t1) and Y (the same person at t2) do not have the same actual memory because Y forgets something which X remembers, but they have the same potential memory because X and Y can have the same memory. Potential memory refers to the ability to remember something, not to our actual memory. That I forget what I have eaten yesterday does not entail that I become a different person, since if asked I can remember what I have eaten. The personal identity consists in the ability to remember something X, namely, the potential memory, rather than consisting in the actual memory. By this reading, consciousness consists of two parts: one is the perception of something X, which constitutes the content of actual memory and potential memory, the other is the ability to remember the perception of X. And we can reformulate the identity criteria: X and Y are the same person if and only if X and Y have the same ability to remember some action or thought.
Bearing this formulation in mind, we can easily reply to the charge of transitivity. The central idea of this charge is that a person X at t3 can remember some of his or her perceptions at t2; it follows that, by Locke’s theory, X at t3 is the same as X at t2. Then, X at t2 can recall his or her perception at t1. It is natural to say that X at t2 is personally identical to X at t1, and with the transitivity of identity, X at t3 is identical with X at t1. However, X at t3 can forget his perceptions and feelings when at t1. If the sameness of memory solely determines the personal identity, X at t3 is not identical with X at t1. Hence, from the above reasoning, we conclude that X at t1 and X at t3 are identical and also non-identical, which is absurd. Hence, Locke’s theory fails.
This reasoning presupposes that actual memory determines the personal identity, and so it misunderstands Locke’s theory. Granted what determines personal identity is the potential memory, that is, the ability to remember. It follows that X at t1 and X at t3 are identical in virtue of the potential memory, since if we asked X and showed previous photos of X to X at t3, X would remember he is the person at t1. Hence, this objection fails if we accept Rickless’s reading.
In this section, I will further deal with two objections to Locke’s personal identity thesis: the objection from false memory and the objection from circularity. First, although Locke defines personal identity in terms of consciousness, it is commonly held that personal identity is defined in terms of memory, where X and Y are identical if and only if X and Y have the same memory. The false memory objection goes as follows. In order for memory to be the criteria for personal identity, the memory in question must be genuine. One day I might have a delusion that I am William Shakespeare and then have the memory of authoring Hamlet, it does not follows that I am Shakespeare unless the memory is real. However, on which ground can we justify our memory as true or false? Normally, we may appeal to logical coherency, since each moment of our memory is causally related, and so we just exclude the incoherent parts in the chain of our memory. I might have more than twenty events which I can recall, and which indicate that I am not Shakespeare, each of which is causally related. Then, I have good reason to regard my remembering being Shakespeare as a delusion. This reply presupposes that most of our memory is real, and so we can rely upon them to exclude some anomalous ones. The thrust of this argument is that we lack criteria to justify whether a memory is real.
By replying to this objection, Locke appeals to the goodness of God to guarantee that such cases do not arise. God will not allow that we can wrongly ascribe actions to ourselves which we did not commit, and so He will not permit the possibility of false memory, as Locke writes, God’s goodness “will not by a fatal error of theirs transfer from one to another, that consciousness, which draws reward and punishment with it” (p. 140). Modern readers will not feel satisfied with Locke’s appeal and they will conclude that Locke cannot respond to this objection and so Locke’s theory fails. In my view, this judgement is too hasty, and there can be a more charitable reading of Locke. To my mind, Locke’s response is reminiscent Moore’s reply to global skepticism. Since radical skeptics claim that we cannot have any knowledge about an external world, and so their claim is on the one hand counterintuitive and on the other hand self-refuting. Advocates for the possibility of global false memory are similar to these skeptics. They, on the one hand, hold that all of our memory may be a total delusion, and on the other hand they cannot provide criteria to distinguish false memory from real memory. If we dismiss their premise, that is, the possibility of global false memory, their objection fails. Because it is counterintuitive to accept the possibility that everything we can recall is false we can exclude the possibility of false memory. Appealing to God for Locke is like our appealing to our healthy common sense. With respect to local false memory, that is, some of our memory might be false, we can just rely on logical coherence of our memory to distinguish the false from the true.
The second objection is that consciousness of personal identity presupposes the personal identity. To be more specific, a person X at time t + 1 recalls the experience of the same person at t; X’s remembering relies upon a notion of personal identity and so we cannot define personal identity in terms of memory. This objection is intuitive. For, how can I recall the event that I was doing my logic test four days ago without the ability to attribute this event to a thinking person, namely, myself. The ability to attribute different events to one agent presupposes personal identity.
This objection also fails to refute Locke. First, Locke argues that the consciousness of personal identity entails personal identity; rather, he argues for the consciousness of a person’s actions and thoughts. Locke does not indicate that X and Y are the same person if and only if X and Y are conscious of being the same person. What he argues is that X and Y are the same person if and only if X and Y are conscious of the same actions and thoughts over time. Second, the ability to attribute different mental states to a person does not presuppose personal identity. This ability might merely indicate a psychological continuity, which is constituted by a chain of causally related mental states (e.g., the consciousness of actions and events) . A causally related chain of memory presupposes personal identity, but explains the personal identity.
Descartes and Locke
I did not find any passage in Descartes’s Second Meditation that indicates personal identity. There might be two reading of his omission. I think Descartes did not discuss personal identity because he saw it as a thesis he needed to argue for, that is, he did not treat it as a problem. It is because a person is identical with a mental and immaterial substance that the problem of personal identity—how a person can remain the same through time and change—does not arise. To be more specific, if a person, in essence, is his/her spirit, an immaterial substance, the substance will not perish and exist independently of changes, and consequently the substance (person) will not lose the identity. I think this line of reasoning is consistent with Descartes’s view.
This view is, nevertheless, objectionable. Assume two mental substances, A and B, having the same mental properties (e.g., thoughts, feelings, memory, and so forth). It is natural to raise a question of if they are the same person. According to Descartes’s theory, they are not the same person because even if they share all mental properties, since the essential difference between A and B is that they are two rather than one substance. What differentiates a substance from another substance is not the suchness and universal properties that other substances can have; rather, it is the oneness that uniquely belongs to one substance to determine a substance’s identity.
Locke differs from Descartes in two respects. First, Locke is concerned with the concept applied to individuals. To put this more accurately, what concerns Locke is the nominal essence of concepts, which specifies the identity criterion of the concept in question. He is not talking about what personal identity is in metaphysical sense; rather, his discussion attempts to be clear about what we can know about personal identity from investigating the nominal essence of person. By contrast, Descartes’s personal identity refers to a metaphysical or objective reality; there is really such a thing as personal identity. Hence, Locke’s accounts of personal identity are more epistemological than Descartes’s, while Descartes is more a metaphysician and less an epistemologist than Locke. Second, Locke distinguishes immaterial or mental substance from person, while Descartes identifies these two things. It is better to examine how Locke makes this distinction.
In Essays, Locke offers two thought experiments to make this distinction. First, according to Locke, it is possible that X is the same person as Y, while X and Y have different mental substances. This means that the consciousness of X can transfer from one mental substance to another mental substance. Furthermore, according to Locke, because everything we know about our mental substances cannot exclude the possibility, we should conclude with him that “it will be possible, that two thinking substances may make but one person” (p. 141). The second thought experiment is similar. It is possible that X is not the same person as Y, while X and Y have the same mental substance. Possibly, a mental substance has different persons inhering within the substance, and so Locke argues that it is possible that the soul or spirit of a person can be identical with the soul of Socrates (p. 141). This is intuitive for us because there exist some people who suffer dissociative identity disorder, which is a mental disorder characterized by the fact that an individual may have more than two independent persona identities. Hence, there is no strong relation between the identity of mental substance and a person’s identity.
Cartesians might reject Locke’s two thought experiments and insist that a person is nothing other than a mental substance, and thus personal identity and mental substance identity are one and the same thing. Locke’s thought experiments rely upon, by using analytic philosophers’ terminology, a kind of modal intuition. It is a commonplace for contemporary analytic philosophers to think that conceivability does not entail possibility. Thus, Cartesians can doubt whether Locke’s thought experiments are really possible. However, Cartesians are no better than Locke, since Descartes’s argument for mind-body substance dualism in Sixth Meditation and his skeptical scenario in First Meditation both depend upon this sort of reasoning, from conceivability to possibility.
On behalf of Locke, I think that Descartes’s view is paradoxical. Granted Descartes’s view that mental substance is person, if one day Descartes lost all of his memory, his mathematics, his philosophy, he remains the same person. We further assume Descartes did not only lose his memory, but also had a memory of a French peasant. It follows, paradoxically from Descartes’s theory, that Descartes still remains the same even if he is not the Descartes we know about and who he would have known about. I do not think this kind of reasoning is convincing and so I am in Locke’s camp.
In sum, this paper dealt with Locke’s personal identity thesis. Section 2 turned to Locke’s relativity of identity thesis and addressed his personal identity theory. In section 3, confronting with two objections to Locke, I provides defense for Locke’s thesis. In section 4, I made a brief comparison between Locke and Descartes, and I argued that Locke’s theory is more persuasive.