Soul theory of diachronic identity

David W. Agler

The Pennsylvania State University

Soul theory

What is a soul?

  • One problem with saying that the person is a soul is: “what is a soul?”
  • Rather than defining it, let’s look at some claims about souls

Traits of the soul

  1. We are souls / spirits
  2. soul is immaterial and distinct from the body
  3. soul always thinks
  4. Bodies are ensouled (acquire souls) at conception
  5. capable of surviving bodily death
  6. the bearer of moral qualities, e.g., wickedness, goodness
  7. the bearer of personal traits, e.g., vices, virtues, likes, dislikes
  8. soul is often said to be a “substance” (type of being that possesses traits)

Soulful theory

Soulful theory

Person \(A\) at \(t_1\) is one and the same person as person \(B\) at \(t_2\) (\(A=B\)) iff \(A\) and \(B\) have the same soul.

Why accept? Reason 1

We are souls.

  • P1. I can doubt everything (including whether I have a physical / material body)
  • P2. I can’t doubt my own existence. The act of my doubting implies a me that doubts.
  • C. Therefore, I am a thinking immaterial being (soul)

Why accept? Reason 2

Allows for strict numerical identity: numerical identity and qualitative identity.

Strict numerical identity

\(A=B\) iff for every property \(F\), \(A\) is \(F\) iff \(B\) is \(F\)

  1. A and B are one and the same object
  2. A and B have all of the same properties

Continued

  • The soul never changes properties.
  • It is capable of “bearing properties” but it does not gain or lose properties.
  • It is thus something that stays exactly the same throughout a person’s life

Reason 3: Egoistic about the afterlife

  • If I associate my continued existence with my body, then concerns about the afterlife are irrational (I just rot)
  • But, souls can potentially exist after death.

Continued

Argument:

  • P1: Concerns about my own existence after death are rational.
  • P2: The only theory that can account for post-mortem existence is the soul theory.
  • C: Therefore, we ought to accept the soul theory.

Exercise

Soulful theory

We have (1) introduced the soul theory and (2) gave some quick arguments for it being true. Answer one of the following:

  1. What other arguments can you think of to support the soul theory?
  2. Which argument did you find the most compelling for the soul theory?

Soul theory: assumptions

  1. we are souls / spirits
  2. the soul is immaterial and distinct from the body (which is material)
  3. the soul .
  4. bodies are ensouled (acquire souls) at conception

Objection 1 - Sleeping

  1. Soul exists (assumption 1)
  2. Soul is always thinking (assumption 3)
  3. We are not always thinking when we are sleeping, in a coma, unconscious, daydreaming, etc.

Objection 2 - The Fetus

  1. Soul exists (assumption 1)
  2. Soul is always thinking (assumption 3)
  3. We are ensouled at conception (assumption 4)
  4. The fetus does not think (science)

Objection 3 - Interaction

  1. Soul exists (assumption 1)
  2. Soul is immaterial (assumpion 2)
  3. Our thoughts control our bodies (intuition)

graph LR
accTitle: Mind-Body Connection
accDescr: Diagram with two nodes, mind and body, with a bidirectional arrow.
    Mind["🧠 Mind"]
    Body["💪 Body"]
    Mind <--> Body

Spooky solutions

Tiny rarefied spirits / liquid that serves as the interface between mind and body (located in pineal gland)

Revision 1: capacity to think

graph LR
accTitle: Mind-Body Connection
accDescr: Diagram with two nodes, mind and body, with a bidirectional arrow.
    Mind["🧠 Always thinking"]
    Body["🧠 Capacity to think"]
    Mind --> Body

Problematic assumption

The soul always thinks

New assumption

The soul has the capacity to think (it is not the mind but the “basis for the mind”)

Fixes the sleeping / unconscious problem.

Interaction problem remains

Does not fix the interaction problem

graph LR
accTitle: Mind-Body Connection
accDescr: Diagram with two nodes, mind and body, with a bidirectional arrow.
    Mind["🧠 Mind"]
    Body["💪 Body"]
    Mind <--> Body

Mind to body

No explanation of how the mind influences the body

Mind to body

No explanation of why damage to body would influence the mind

If I’m intoxicated, why would it impact my ability to think?

Fetus problem

“capacity to think” is ambiguous

graph LR
accTitle: Mind-Body Connection
accDescr: Diagram with three nodes, Capacity nodes points to Capability and Potentiality nodes.
    Mind["🧠 Capacity"]
    A["Capability"]
    B["Potentiality"]
    Mind --> A
    Mind --> B

Capability

S has the capacity (capability) to do action \(A\) if \(S\) has the power to do \(A\) without any change to the intrinsic properties of \(A\) (only a change to the extrinsic properties / conditions).

Potentiality

\(S\) has the capacity (potentiality) to do action \(A\) if some change to \(S\) would give \(S\) the power to do \(A\)

Example: Speaking French

  • Liz has the “capacity” (capability) of speaking French. She’s a native speaker so she has the power but is not exercising it.
  • Tek has the “capacity” (potentiality) of speaking French. He could learn French through study / immersion.

Example: Lifting heavy weight

  • Liz has the capability of benching 200lbs
  • Sam has the potential

Question

Create your own example that illustrates the difference between “capability” and “potentiality”

Fetus problem (again)

  1. If being a soul requires capability, then fetus does not have a soul (same with brain dead people)
  2. If being a soul requires potentiality, then countless entities are ensouled, e.g., animals (via genetic engineering), brain dead people

Revision 2: no thought

graph LR
accTitle: Soul theory revisions
accDescr: Diagram with three nodes, noting the revisions to the soul theory. Always thinks to Capacity to think to Does not think.
    Mind["🧠 Always thinks"]
    A["Capacity to think"]
    B["Does not think"]
    Mind --> A
    A --> B

The soul is thus neither the mind (since it does not think) nor the basis for the mind (since it is not the capacity for thinking).

Objection - Soul is nothing

The soul does not appear to be anything at all.

  • Does not think
  • Is not the capacity for thought
  • Just an empty container with no properties

Something with no properties does not exist.

Objection - Identical twins

graph LR
accTitle: Twins problem
accDescr: Diagram pointing out that a single zygote forms into two embryos and each embryo forms into its own person
    Z["Zygote (Conception)"]
    A["Embryo 1"]
    B["Embryo 2"]
    A1["Person 1"]
    B1["Person 2"]
    Z --> A
    Z --> B
    A --> A1
    B --> B1

If a body (zygote) is ensouled at conception, then there is one soul created. But, we have two people.

Twins - Ackshually…

  1. two souls at conception but they both occupy the same body. Problem: This allows for two people to occupy a single body
  2. one soul at conception which is shared by two adults. Problem: Identical twins are one person in two bodies.
  3. one soul at conception which goes with one of the twins. Problem: One of the twins is not a person.

Objection: Wild possibilities

If the soul is just an empty container (not bound to thoughts, psychology), then it allows for “wild possibilities”:

  1. Reincarnation without remembering prior selves
  2. Day-night man scenario

Review and final say

  • We’ve given some arguments for and against the soul theory (you stay the same person because of your soul)
  • What do you think? Does our survival depend upon having the same soul or something else: psychology / mind, body, etc.?