A Swinburne-Like Dualistic Argument

 

  1. (Premise) x splits into y and z.
  2. (Premise) One of the following is true:
    1. x=y and x¹z
    2. x=z and x¹y
    3. x=y and x=z
    4. x¹y and x¹z
  3. (Premise) A purely physical description of the world is insufficient to explain which one of (a)-(d) is true.
  4. Therefore, a purely physical description of the world is incomplete.

 

Note 1: This argument is invalid.  It needs an auxiliary premise.  What is it?

Note 2: If (1) is not actually true, then the conclusion is that a physical description of the world would be incomplete if (1) were true.

 

Parfit’s Survival Argument

 

  1. (Premise) x splits into y and z.
  2. (Premise) x survives.
  3. (Premise) If survival is the later existence of something identical, then one of the following is true:
    1. x=y and x¹z
    2. x=z and x¹y
    3. x=y and x=z
    4. x does not survive
  4. (Premise) But (a)-(c) are false.
  5. Therefore, if survival is the later existence of something identical, x does not survive. (By 3 and 4)
  6. Therefore, survival is not the later existence of something identical. (By 2 and 5)

 

Note: If (1) is not actually true, but only possibly true, then the conclusion is that survival need not be the later existence of something identical.

 

Parfit’s Not Mattering Argument

 

  1. (Premise) If identity (rather than psychological continuity/connectedness) is what matters to persons, then identity (rather than psychological continuity/connectedness) is what matters in all possible situations.
  2. (Premise) It is not the case that identity (rather than psychological continuity/connectedness) is what matters in all possible situations.
  3. Therefore, identity (rather than psychological continuity/connectedness) is not what matters to persons.

 

Hume’s Predictability Argument

 

  1. (Premise) If actions are not determined by one’s character and external circumstances, then they are not predictable.
  2. (Premise) Actions are predictable.
  3. Therefore, actions are determined by one’s character and external circumstances.

 

A Humean Responsibility Argument

 

  1. (Premise) If an action is not determined by one’s character and external circumstances, then the action is a matter of chance.
  2. (Premise) If an action is a matter of chance, then one is not responsible for it.
  3. Therefore, if one is responsible for an action, then the action is determined by one’s character and external circumstances.