Combining Philosophers

All the ideas for Paul Bernays, Feferman / Feferman and Derek Parfit

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28 ideas

2. Reason / E. Argument / 7. Thought Experiments
Imaginary cases are good for revealing our beliefs, rather than the truth [Parfit]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Very few things in set theory remain valid in intuitionist mathematics [Bernays]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Restricted Platonism is just an ideal projection of a domain of thought [Bernays]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Mathematical abstraction just goes in a different direction from logic [Bernays]
7. Existence / C. Structure of Existence / 2. Reduction
Reduction can be by identity, or constitution, or elimination [Parfit, by PG]
16. Persons / B. Nature of the Self / 5. Self as Associations
Personal identity is just causally related mental states [Parfit, by Maslin]
16. Persons / D. Continuity of the Self / 1. Identity and the Self
Psychologists are interested in identity as a type of person, but philosophers study numerical identity [Parfit]
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
One of my future selves will not necessarily be me [Parfit]
If my brain-halves are transplanted into two bodies, I have continuity, and don't need identity [Parfit]
Over a period of time what matters is not that 'I' persist, but that I have psychological continuity [Parfit]
16. Persons / D. Continuity of the Self / 4. Split Consciousness
If we split like amoeba, we would be two people, neither of them being us [Parfit]
It is fine to save two dying twins by merging parts of their bodies into one, and identity is irrelevant [Parfit]
If two humans are merged surgically, the new identity is a purely verbal problem [Parfit]
16. Persons / D. Continuity of the Self / 5. Concerns of the Self
Concern for our own lives isn't the source of belief in identity, it is the result of it [Parfit]
16. Persons / E. Rejecting the Self / 4. Denial of the Self
It doesn't matter whether I exist with half my components replaced (any more than an audio system) [Parfit]
23. Ethics / E. Utilitarianism / 1. Utilitarianism
We should focus less on subjects of experience, and more on the experiences themselves [Parfit]