Combining Texts

All the ideas for 'On the Question of Absolute Undecidability', 'Carnap and Logical Truth' and 'Morality as system of hypothetical imperatives'

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20 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
Mathematical set theory has many plausible stopping points, such as finitism, and predicativism [Koellner]
'Reflection principles' say the whole truth about sets can't be captured [Koellner]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
In order to select the logic justified by experience, we would need to use a lot of logic [Boghossian on Quine]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Elementary logic requires truth-functions, quantifiers (and variables), identity, and also sets of variables [Quine]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Logical consequence is marked by being preserved under all nonlogical substitutions [Quine, by Sider]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
If logical truths essentially depend on logical constants, we had better define the latter [Hacking on Quine]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
We have no argument to show a statement is absolutely undecidable [Koellner]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / a. Set theory paradoxes
Set theory was struggling with higher infinities, when new paradoxes made it baffling [Quine]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
There are at least eleven types of large cardinal, of increasing logical strength [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
PA is consistent as far as we can accept, and we expand axioms to overcome limitations [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Arithmetical undecidability is always settled at the next stage up [Koellner]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
If set theory is not actually a branch of logic, then Frege's derivation of arithmetic would not be from logic [Quine]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
Commitment to universals is as arbitrary or pragmatic as the adoption of a new system of bookkeeping [Quine]
10. Modality / A. Necessity / 6. Logical Necessity
Frege moved Kant's question about a priori synthetic to 'how is logical certainty possible?' [Quine]
12. Knowledge Sources / A. A Priori Knowledge / 7. A Priori from Convention
Examination of convention in the a priori begins to blur the distinction with empirical knowledge [Quine]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / e. Ethical cognitivism
Morality is inescapable, in descriptive words such as 'dishonest', 'unjust' and 'uncharitable' [Foot]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / b. Rational ethics
Reason is not a motivator of morality [Foot, by Hacker-Wright]
Rejecting moral rules may be villainous, but it isn't inconsistent [Foot]
23. Ethics / D. Deontological Ethics / 1. Deontology
Saying we 'ought to be moral' makes no sense, unless it relates to some other system [Foot]
23. Ethics / D. Deontological Ethics / 4. Categorical Imperative
Morality no more consists of categorical imperatives than etiquette does [Foot]