Week 9 The self

Prep and homework Ans.

Topic 09 Parfit. 1995. Reductionism and personal identity

Personal identity

Fundamentality
What kind of thing am I.

Human being 💡
Brain
Mental states 💡
1. Reverse life
2. Teletransportation 💡
Soul #extra
Eliminatinism #extra (SEP Entry Eliminatinism)
Reductionism #extra
Identity Theory (In Previous Notes)

Julius: In case of confusion over all so far in this course, plz go back to Physicalism
💡 are for key points to cover in presentation ~~as suggestion.~~

Human being

Substance Sortal: Sortals (Stanford Encyclopedia of Philosophy)

Sortal (Click to expand)

A "sortal" is a term, concept, or property that helps us categorize and individuate objects in the world. It provides criteria for counting objects of a certain kind, determining their identity over time, and understanding their essential nature. Sortals can range from specific terms like "dog" or "chair" to more general categories like "animal" or "furniture." They are often contrasted with mass terms, which refer to undifferentiated substances like "water" or "gold." The concept of sortals is important in philosophy for understanding how we carve up the world into distinct objects and how we track their persistence through change. It also has implications for issues like identity, modality, and the relationship between language and thought. However, there is ongoing debate about the precise definition of "sortal" and the extent to which it aligns with linguistic categories like count nouns or with metaphysical notions like essence.

From Parfit. 1995. Reductionism and personal identity

Distinction between qualitative identity and quantitative identity.
What makes a particular thing "that particular thing". ("Two white billiard balls" from Topic 09 Parfit. 1995. Reductionism and personal identity)

The relation between a person of one time and a person of another time. (aka. Ship of Theseus)

graph TD
    A("Original Person (0%)") --> |30% Replaced| B("30% Replaced")
    B --> |20% Replaced| C("50% Replaced")
    C --> |20% Replaced| D("70% Replaced")
    D --> |30% Replaced| E("Replica (100% Replaced)")

    style A fill:#f9f,stroke:#333,stroke-width:2px
    style B fill:#f96,stroke:#333,stroke-width:2px
    style C fill:#9f6,stroke:#333,stroke-width:2px
    style D fill:#69f,stroke:#333,stroke-width:2px
    style E fill:#ccf,stroke:#333,stroke-width:2px

    classDef person fill:#ddd,stroke:#333,stroke-width:1px
    class A,B,C,D person

    classDef replica fill:#ccf,stroke:#333,stroke-width:1px
    class E replica

Metaphysical Question vs. Language

出处：Material Constitution (Stanford Encyclopedia of Philosophy)

Example

The Puzzle of the Statue and the Clay

"Lump" -> "David" -> Pancake

Core puzzle: They are distinct entities despite sharing the same matter. So Constitution is not Identity.

The grounding problem: How to explain how David and Lump can differ in their properties (e.g., persistence conditions) if they are materially identical?

Julius: Molecules and substance exist independent from how I refer to it. How can we define its "surviving" status, before and after the flattening.

Possibility of applying multiple descriptions to the same physical entity as it undergoes transformations. While the physical substance persists, the applicability of certain sortal terms (e.g., "David") might change or become indeterminate.

Solutions to Lump & David Puzzle

1. The Constitution View (Wiggins, Baker, and others):

P1: David (the statue) did not exist on Monday.
P2: Lump (the clay) did exist on Monday.
C1: David is identical to Lump.
Conclusion: Therefore, David is not identical to Lump (~C1).

TLDR: Constitution is a relation of dependence, where the statue is "nothing over and above" the lump of clay, but not a relation of identity.

2. Mereological Essentialism (Chisholm):

P1: The parts that compose David on Tuesday were present on Monday.
P2: If the parts that compose David on Tuesday were present on Monday, then David existed on Monday.
C1: David did not exist on Monday.
Conclusion: Therefore, David did exist on Monday (~C1).

TLDR: The whole is essential to the parts, meaning that whenever you have the same parts, you have the same whole.
...

There are 5 proposed solutions to this puzzle. For more, go to note The Puzzle of the Statue and the Clay

Brain

Thought Experiment: Brain Transplant

Is it you acquiring a new body, or the donor acquires a new brain as an organ transplant?
If you define a person by solely brain, is it the full body or just a part of it? Which part of the body is actually "me"?

Phase Sortal way: Being a professor for part of my life, and "driving in sort of a car" for part of my life.

Mental states

aka. Memories in this context.

The two approaches to mental states:

Reverse life

Jeff McMahan, The Ethics of Killing: Problems at the Margins of Life - PDF at phil-docs.zhuo.li
At which point of such "reversing life until back to womb" process, will "you" be gone?

More Info for Discussion（点击展开）

Imagine a life lived in reverse, where you gradually regress from adulthood to infancy, your memories fading, your experiences diminishing, and your sense of self slowly dissolving. This thought experiment, inspired by McMahan's "reverse life" scenario, challenges our understanding of the self and its persistence through time. If we are essentially embodied minds, as the Embodied Mind Account suggests, our existence is contingent on the physical and functional continuity of our brains. As we regress in the reversed life, the neural substrate that supports our consciousness and memories gradually deteriorates, leading to a weakening of the prudential unity relations that bind us to our past and future selves. This raises the question: at what point in this process of regression does the self cease to exist? Is there a specific moment when "you" are gone, or is it a gradual fading away? This thought experiment highlights the fragility and impermanence of the self, suggesting that it is not a fixed entity but rather a dynamic process dependent on the ongoing functioning of our brains and the continuity of our experiences. It invites us to consider the nature of personal identity and the value we place on the continuity of the self in the face of inevitable change and eventual dissolution.

Teletransportation

为什么需要提到沙堆悖论

Language doesn't always sharply apply to things that are kind of in-between something in real world. (In a clear-cut way). So is the futility of language in sharply making a cut on the transformation of people. How our concepts can become vague and indeterminate when applied to continuous variations.

Two cases of Teletransportation 两种形式的复制人

graph LR
A[Original Person] -->|Scanning & Replication| B(Replica 1)
A -->|Scanning & Replication| C(Replica 2)
A --> A1[Life of Original Person]
subgraph Possible Futures
B --> B1[Life 1]
B --> B2[Life 2]
B --> B3[Life 3]
C --> C1[Life 4]
C --> C2[Life 5]
C --> C3[Life 6]
end

style A fill:#f9f,stroke:#333,stroke-width:2px
style B fill:#f96,stroke:#333,stroke-width:2px
style C fill:#9f6,stroke:#333,stroke-width:2px

classDef replica fill:#ccf,stroke:#333,stroke-width:1px
class B,C replica

classDef future fill:#ddd,stroke:#333,stroke-width:1px
class A1,B1,B2,B3,C1,C2,C3 future

graph LR
A[Original Person] -->|Scanning & Replication| B(Replica)
A -->|He is destroyed by the tele machine| X
subgraph Possible Futures
B --> B1[Life 1]
B --> B2[Life 2]
B --> B3[Life 3]
end

style A fill:#f9f,stroke:#333,stroke-width:2px
style B fill:#f96,stroke:#333,stroke-width:2px

classDef replica fill:#ccf,stroke:#333,stroke-width:1px
class B replica

classDef future fill:#ddd,stroke:#333,stroke-width:1px
class B1,B2,B3 future

结合课堂上关于 Personal Identity 的几种进路分析 Teletransportation：

Survival and Identity 回到 Survival的问题，也就是最开始的捏泥巴问题: Does the original person survive the teleportation process? Is the replica the same person as the original, or is it a new individual with the same memories and personality?
The Role of Bodily Continuity: How important is bodily continuity for personal identity? Does the destruction of the original body entail the death of the original person, even if a qualitatively identical replica exists?
Mental States 心理角度: Does the replica have a genuine sense of self that is continuous with the original person's sense of self? How does the transfer of memories and psychological characteristics affect our understanding of the self and its persistence?

Recap on answer to Teletransportation topic (From my perspective)

Answer (Click to expand)

Whether teletransportation would kill you depends on your definition of "you." If you believe personal identity is solely based on bodily continuity, then yes, teleportation would result in your death, as your original body is destroyed. However, if you subscribe to a reductionist view of personal identity, where continuity of consciousness and psychological connectedness are paramount, then the person who materializes on Mars, with your memories and personality, could be considered a continuation of "you." Personally, I lean towards the reductionist view. While the destruction of my physical body would be a significant event, the continuation of my consciousness and experiences would mean that "I" still exist, albeit in a different location and physical form. Therefore, while I acknowledge the strangeness of the process, I wouldn't necessarily consider teleportation as death, and the potential benefits of instantaneous travel might outweigh the metaphysical peculiarity of the situation.