Personal Identity

个人同一性的问题涉及到一个人随着时间的推移而继续存在的问题。或者，换句话说，在人格同一性中，我们试图为诸如“是什么让一个人在时间t1与另一个人在时间t2成为同一个人？”当代最重要的人格同一性理论之一被称为心理标准。根据心理学的标准，一个人的持续存在是由“心理连续性”构成的。换句话说，t2时的B和t1时的A是同一个人如果B的心理状态和A的心理状态有足够的因果关系。近年来，心理标准受到了猛烈的攻击。最近很多关于人格同一性的研究都质疑心理学标准对于你是谁和你也是谁之间关系的充分性。标准版本的心理学标准区分了这两件事，并认为它们是不同的。他们这样做是因为各种各样的思想实验，比如约翰·洛克的故事，一个王子和一个皮匠的思想互换了位置。现代洛克主义者从这个故事中得出的结论是，如果这在逻辑上是可能发生的（即使在技术上是不可能的），那么人和他们的身体就不可能是一回事。但这就提出了一个问题，人是什么，如果它与身体或大脑不是一回事，如果它不被视为传统的非物质灵魂。大多数心理学理论家希望坚持人是某种物理对象，但由于他们坚持认为人和身体是不同的，他们也坚持明显违反直觉的观点，即存在两种不同的物理对象，即人和身体。但是为什么看起来只有一个物理对象与我们的存在有关呢？他们的解决方案是采用“构成理论”，并声称虽然有两个物理对象，但它们共享相同的物质和相同的空间。然而，它们仍然是不同的，因为一个存在而另一个不存在是可能的。我认为心理标准与构成理论是不相容的。一方面，根据心理学的标准，人的存在条件是心理的，而物理对象的存在条件不是心理的。我还指出，心理学标准允许人们可以“交换身体”，但假设一个物理对象可以交换身体是没有意义的。相反，我发展了另一个版本的心理学标准，根据这个标准，一个人是一系列的精神状态和事件。然后我会证明，在这个理论中，虽然人不是字面上的物质，但人仍然是一个实体，其存在方式与物质的存在方式相似。这样的实体我称之为“准物质”。我也为心理学标准辩护，反对对它的一些反对意见，但我最后提出了一个重要的新问题。某些有影响力的心理学理论家希望降低继续存在的重要性，以支持他们所说的“生存中重要的东西”，他们称之为“关系R”。R被定义为“心理上的连通性和/或连续性”，他们希望让R与持续存在不同，成为一个程度问题。然而，我认为，对于“心理连通性和/或连续性”的含义有各种各样的解释，它们都不符合这样一个原则，即既然生存中重要的东西是非常重要的，那么我们是否拥有生存中重要的东西就不能取决于一个微不足道的事实，这是这类心理学理论家所使用（和要求）的原则。

The issue of personal identity concerns the issue of what constitutes the continued existence of a person over time. Or, to put it another way, in personal identity we seek to provide answers to questions such as 'What makes a person A at time t1 the self-same person as a person B at a later time t2?'.One of the most important contemporary theories of personal identity is known as the psychological criterion. According to the psychological criterion a person's continued existence is constituted by 'psychological continuity'. In other words, B at t2 is the self-same person as A at t1 if enough of B's psychological states are causally related to A's psychological states in the right sort of way.In recent years the psychological criterion has been subject to vigorous attack. Much recent work in personal identity has questioned the adequacy of the psychological criterion's account of the relation between the person you are and human being you also are. The standard version of psychological criterion distinguishes between these two things and takes them to be distinct. They do this because of various thought experiments, such as John Locke's story of the minds of a prince and a cobbler swapping places. The conclusion that modern Lockeans draw from this story is that if it is logically possible that this could happen (even if it is not technically possible), then a person and their body cannot be the same thing. But this raises the question of what is the person, if it is not the same thing as the body or the brain, and if it is not conceived of as a traditional non-physical soul.Most psychological theorists wish to maintain that the person is a physical object of some sort, but as they are committed to the view that the person and body are distinct, they are committed to the apparently counter-intuitive view that two distinct physical objects exist, the person and the body. But how is it that there only appears to be one physical object associated with our existence? Their solution to this is to adopt a 'constitution theory' and claim that although there are two physical objects, they share the same matter and the same space. They are nevertheless distinct, however, because it is possible that one could exist when the other does not.I argue that the psychological criterion is not compatible with the constitution theory. For one thing, according to the psychological criterion the existence conditions of people are psychological, but the existence conditions of physical objects are not. I also point out that the psychological criterion allows that people can 'body-swap', but it does not make sense to suppose that a physical object can body-swap.I develop instead an alternative version of the psychological criterion, according to which a person is a series of mental states and events. I then show that on this theory, that while a person is not literally a substance, a person is nevertheless an entity that exists in a way that is akin to the way that substances exist. Such an entity I call a 'quasi-substance'.I also defend the psychological criterion against a number of objections to it, but I finish by developing a significant new problem for it. Certain influential psychological theorists wish downgrade the importance of continued existence in favour of what they say is 'what matters in survival', which they claim is 'Relation R'. R is defined as being 'psychological connectedness and/or continuity', and they wish to make R, unlike continued existence, a matter of degree. I argue, however, that there are various interpretations of what 'psychological connectedness and/or continuity' mean, and that none of them are consistent with the principle that since what matters in survival is of great significance, whether we have what matters in survival cannot depend on a trivial fact, a principle which is used (and required) by this sort of psychological theorist.