Are we free?

David W. Agler

The Pennsylvania State University

Impossibilism

Three version of impossibilism

Impossibilism

Free will is impossible.

  1. Strong inevitabilism
  2. Weak inevitabilism
  3. Contemporary fatalism

Strong inevitalibism

Stronly inevitable

An event \(E\) is strongly inevitable for \(S\) if and only if \(E\) will happen no matter what. That is, if an event \(E\) is strongly inevitable for \(S\), then there is nothing anyone can do to prevent \(E\) from occurring.

Examples

  1. Death
  2. Taxes
  3. Remote cosmic events

van Inwagen’s Example

  1. You plan to go to the beach
  2. You enter witch’s hovel
  3. Prophecy: You will drown within 24 hours

flowchart LR
    A[Prophecy]
    M[Run to highest mountain]
    S[Stay with witch]
    B[Go to the beach]
    D[Drown]
    A --> M & S & B
    M & S & B --> D

Strongly inevitable event

Stronly inevitable

Create a story where a person is “fated” (in the strong inevitable sense) to do some action.

Lazy (Idle) Argument1

  • P1: Fated to recover from the illness or fated to not recover.
  • P2: If fated to recover, then it does not matter whether you consult a doctor (nothing you or anyone else can do to prevent it)
  • P3: If not fated to recover, then it does not matter whether you consult a doctor.
  • C: Therefore, it is pointless to contact a doctor.

Lazy Argument, Metaphysics Class

  • It is either strongly inevitable that I will pass Metaphysics or fail it.
  • I don’t know which one.
  • Let’s reason through the possibilities

Case 1 (Pass)

Suppose it is strongly inevitable (SI) that I will pass my Metaphysics class.

flowchart LR
    D[Do homework]
    N[Don't do homework]
    P[Pass class]
    F[Fail]
    X[Doesn't matter]
    D -.-> P
    N -.-> P
    P --> X

  • If I do homework, I’ll pass.
  • If I don’t do homework, I’ll pass
  • So, it does not matter whether I do my homework.

Case 2 (Fail)

Suppose it is strongly inevitable that I will fail my Metaphysics class.

flowchart LR
    D[Do homework]
    N[Don't do homework]
    P[Pass class]
    F[Fail]
    X[Doesn't matter]
    D -.-> F
    N -.-> F
    F --> X

  • If I do homework, I’ll fail.
  • If I don’t do homework, I’ll fail.
  • So, it does not matter whether I do my homework.

Proof by Cases

  • In both cases, it does not matter whether I do my homework.
  • So, even though I don’t know whether I will pass or fail, I shouldn’t worry about doing my homework.

Lazy Argument

Exercise

Create your own lazy argument.

Strongly inevitabilism

Stronly inevitabilism

Every event \(E\) is strongly inevitable: For every event \(E\), there is nothing you, or I, or anyone else can do to prevent \(E\).

  • Maybe some events are strongly inevitable (death, God’s judgment)
  • Strong inevitabilism says every event is strongly inevitable.

Problem 1: Hasty Generalization

  1. Hasty generalization: X is F. Therefore, everything is F.
  2. Example: John is a man and he’s a jerk. Therefore, all men are jerks.
  3. Example: X is SI. Therefore, every event is SI

Problem 2: Vague

Events that seem SI are only vaguely stated.

  1. Maybe we know that death (in general) is SI
  2. But no knowledge of specific SI deaths.
  3. Tek will die tomorrow in a car crash (driving a blue Honda Civic) at precisely 5:02 PM EST

Problem 3: Too strong (breaks cause and effect)

If \(E\) is SI, then there is nothing anyone can do to prevent \(E\).

  • Suppose it is SI Tek will crash his car tomorrow.
  • Surely, there is something he can do: not drive.
  • There is a possible world where he does not drive and so does not crash.

If SI were true, then events would happen (crash) regardless of the cause (driving)

Weak inevitabilism

Weakly inevitable

A future event \(E\) (an event that is going to happen) is weak inevitable iff

  1. \(E\) is not strongly inevitable (whether \(E\) will happen depend upon what \(S\) does). If \(S\) acted differently, \(E\) can fail to occur.
  2. In any scenario where \(S\) tries to prevent \(E\) from occurring, then \(S\) will always choose the wrong method for preventing \(E\) because \(S\) is ignorant of the right method for preventing \(E\).
  3. it is strongly inevitable that \(S\) is ignorant of the right way to prevent \(E\).

WI is somewhat hard to understand.

Weak inevitabilism - Clause 1

A WI is not SI.

  • An event \(A\) can be WI for \(S\) but it is possible that \(S\) did \(B\) instead of \(A\).
  • There are some possible worlds where \(S\) does \(B\) instead of \(A\).

Example

  • Tek eats sandwich
  • Possible that Tek ate lasagna instead

Weak inevitabilism - Clause 2

If \(A\) is WI, then \(S\) is ignorant of how to do not-\(A\).

Example

  • Tek eats sandwich
  • Possible that Tek ate lasagna instead
  • But Tek is ignorant of how to eat lasagna instead of the sandwich.

Weak inevitabilism - Clause 3

The fact that \(S\) is ignorant of how to prevent a weakly inevitable event \(A\) is strongly inevitable.

Example

  • Tek eats sandwich
  • Possible that Tek ate lasagna instead
  • He is ignorant of how to not eat a sandwich.
  • There is no possible world where he would have the knowledge of how to avoid eating the sandwich.

Weak inevitablism

Weakly inevitabilism

All events are weakly inevitable.

Possible to prevent them, but there is nothing anyone can do to gain the knowledge about how to prevent them.

  • We could prevent X
  • But we’d need knowledge we never could have (?)

Weak inevitabilism - Example 1

  • Prophecy: A witch tells you that you will drown (WI).
  • Possible that you could prevent your drowning (staying with witch).
  • However: to prevent drowning, you walk up a mountain
  • You trip and fall into the well.
  • It is SI that you lack the knowledge to prevent drowning.

Weak inevitabilism - Example 2

flowchart LR
    B[Burning building]
    N[Do nothing]
    C[Close exit]
    F[Far exit]
    D[Death]
    L[Live]
    B ==> C ==> D
    B -.-> N -.-> D
    B -.-> F -.-> L

  • You could prevent death (go to far exit)
  • But there is nothing anyone can do to prevent that you will be ignorant of the right way to prevent death.

Problem - Speculative

  • The theory is speculative
  • Why is nothing anyone can do to prevent me being ignorant of the right way to prevent some event?

Example

  1. Writing a completeness proof (suppose WI)
  2. Possible for me to stop but I’m ignorant about how (nothing anyone can do about this)
  3. Um, no. I can just put my pen down.

Problem - Mechanism

  • Theory needs to specify what is keeping me from acting otherwise in both this world and other worlds
  • The nature of the world? God?

Extra credit (“You can’t fight fate”)

Extra credit

Various pieces of literature utilize the theme that you “can’t fight your fate”.

Example: Oedipus. Oracle states that Oedipus would kill his father and sleep with his mother. Oedipus tried to avoid this by staying away from his father. Ultimately fulfills the prophecy.

Find another piece of literature, film, TV show, anime / manga, etc. and briefly explain how it explores this theme.

Fatalism

Fatalism

  • Last time: strong inevitablism and weak inevitablism.
  • This time: fatalism.
  • Goals
    1. Understand fatalism
    2. Evaluate arguments for fatalism
    3. Decide if we are fated.

Fatalism defined

Fatalism

For every person \(S\) each of their actions is fated.

Fated

A future action \(E\) is fated for a person \(S\) if and only if there is an extra-worldly fact that makes it such that \(S\) cannot do not-\(E\).

Fatalism clarified

  1. Free will is impossible.
  2. The force that keeps us free is extra-worldly
  3. Says nothing about possible worlds (counterfactual scenarios): just that in this world we cannot act otherwise.

Argument 1.

The first argument we will consider has several names:

  1. From the principle of bivalence
  2. From the inability to change the truth value of a proposition
  3. Logical argument for fatalism

It has three steps.

Step 1. Bivalence clarified

Bivalence

The principle of bivalence is the principle that every proposition is either true or false (not both and not neither).

  • David is 6’0.
  • Emmanuel Macron is the current president of France.
  • I ran six miles yesterday.

Step 2. Inability to change truth values.

Can’t change truth values

There is nothing anyone can do to change the truth value of a proposition.

  • David is 6’0 at such-and-such time at such-and-such date.
  • Emmanuel Macron is the current president of France (at the moment this sentence is uttered).
  • I ran six miles yesterday (10/20/26).

Step 2 continued

Some propositions are about the future. Suppose the following is True:

Tek eats a sandwich on 1 July 2040.

If POB, then:

  1. When Tek is born, it is true that Tek eats a sandwich on 1 July 2040.
  2. When Tek is 12, it is true that Tek eats a sandwich on 1 July 2040.
  3. When Tek is 14, it is true that Tek eats a sandwich on 1 July 2040.

Step 2 continued

Strange to say that the truth value changes:

  1. When Tek is born, it is TRUE that Tek eats a sandwich on 1 July 2040.
  2. When Tek is 12, it is FALSE that Tek eats a sandwich on 1 July 2040.
  3. When Tek is 14, it is TRUE that Tek eats a sandwich on 1 July 2040.

Step 3 - the argument

  1. “Tek eats sandwich on 1 July 2040” is either T or F.
  2. Tek has no power to change the truth value of (1).
  3. If (1) is T and Tek has no power to change (1), then Tek has no power to not eat a sandwich.
  4. If (1) is F and Tek has no power to change (1), then Tek has no power to eat a sandwich.
  5. In both cases, Tek has no power to act otherwise.
  6. Therefore, Tek is not free.

Step 3 - the argument visualized

flowchart LR
    B["Tek eats sandwich"]
    T[True]
    F[False]
    C[Can't do otherwise]
    B ==> T ==> C
    B ==> F ==> C

The extra-worldly fact that makes free will impossible comes from “logic”:

  1. The principle of bivalence
  2. The inability to change truth values

Step 3 - the argument visualized

Book with your whole life written in it (birth, mid-life, death).

Exercise

Exercise

  1. Consider the proposition “you meet the love of your life on Thanksgiving break”.
  2. Using this proposition, recreate the argument from the inability to change the truth of a proposition.

Taylor’s logical fatalism

Taylor’s logical fatalism

The book discusses “Taylor’s logical fatalism”.

  • Reconstruct this argument
  • Is it any different than the previous argument?

Theological fatalism

Theological fatalism

Recall that fatalism says that some extra-wordly force makes free will impossible.

  1. Logic: bivalence, inability to change truth values
  2. God

“In this world, is the destiny of mankind controlled by some transcendental entity, or law? Is it like the hand of God hovering above?” - Berserk

Assumptions about God

  1. God is omniscient: knows everything
  2. God is eternal: is everywhere
  3. God knows everything by seeing everything (not by reasoning)1

Proposition (3) is important because if the world were indeterministic, then not even God could deduce the future.

Argument

  • P1: If God is omniscient, then God knows whether I will do X or not-X.
  • P2: If God knows whether I will do X or not-X and I will do X, then it is necessarily the case that I will do X.
  • P3: If God knows whether I will do X or not-X and I will do not-X, then it is necessarily the case that I will do not X.
  • IC: Therefore, it is either necessary that I will do X or necessary that I will do not-X.

Argument continued

  • P4: If it necessary that I will do X, then it is not possible for me to do not-X.
  • P5: If it necessary that I will do not-X, then it is not possible for me to do X.
  • IC2: Therefore, it is not possible for me to do not-X or not possible for me to do X.
  • P6: If I am free to do X (or not-X), then it is possible for me to do X and possible for me to do not-X (Contradiction with IC2).
  • C: Therefore, if God is omniscient and eternal, then freedom is impossible (fatalism is true).

Theological Fatalism (diagram)

flowchart LR
    G[God]
    A["knows I will do X"]
    Ai["Can't do not-X"]
    I[Impossible to do otherwise]
    B["knows I won't do X"]
    Bi[Can't do X]
    I[Impossible to do otherwise]
    NF[Not Free]
    G ==> A ==> Ai ==> I ==> NF
    G ==> B ==> Bi ==> I ==> NF

Ways out?

Not clear how we can be free if God is eternal and omniscient.

  1. Get God to have false beliefs (but it would conflict with omniscience)
  2. Get God to have no beliefs about the future (rather than false knowledge), then maybe (conflicts with omniscience - sort of)
  3. Get God to not exist (Kill God)
  4. No future

Does fate exist?

“In this world, is the destiny of mankind controlled by some transcendental entity, or law? Is it like the hand of God hovering above?” - Berserk

Exercise

Do you believe in fate? Are our lives ruled by some extra-worldly power (logic, God, some other force)?