Combining Texts

All the ideas for 'Pens��es', 'Intro to 'The Reason's Proper Study'' and 'Which Logic is the Right Logic?'

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38 ideas

2. Reason / A. Nature of Reason / 9. Limits of Reason
The heart has its reasons of which reason knows nothing [Pascal]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / c. Grelling's paradox
If 'x is heterological' iff it does not apply to itself, then 'heterological' is heterological if it isn't heterological [Hale/Wright]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
The incompletability of formal arithmetic reveals that logic also cannot be completely characterized [Hale/Wright]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
If structures are relative, this undermines truth-value and objectivity [Hale/Wright]
The structural view of numbers doesn't fit their usage outside arithmetical contexts [Hale/Wright]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
The neo-Fregean is more optimistic than Frege about contextual definitions of numbers [Hale/Wright]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Objects just are what singular terms refer to [Hale/Wright]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
The first principles of truth are not rational, but are known by the heart [Pascal]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstracted objects are not mental creations, but depend on equivalence between given entities [Hale/Wright]
19. Language / E. Analyticity / 2. Analytic Truths
Many conceptual truths ('yellow is extended') are not analytic, as derived from logic and definitions [Hale/Wright]
19. Language / F. Communication / 1. Rhetoric
We only want to know things so that we can talk about them [Pascal]
21. Aesthetics / C. Artistic Issues / 3. Artistic Representation
Painting makes us admire things of which we do not admire the originals [Pascal]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
It is a funny sort of justice whose limits are marked by a river [Pascal]
22. Metaethics / B. Value / 1. Nature of Value / d. Subjective value
Imagination creates beauty, justice and happiness, which is the supreme good [Pascal]
22. Metaethics / C. The Good / 2. Happiness / d. Routes to happiness
We live for the past or future, and so are never happy in the present [Pascal]
23. Ethics / F. Existentialism / 3. Angst
If man considers himself as lost and imprisoned in the universe, he will be terrified [Pascal]
24. Political Theory / D. Ideologies / 5. Democracy / a. Nature of democracy
Majority opinion is visible and authoritative, although not very clever [Pascal]
25. Social Practice / A. Freedoms / 5. Freedom of lifestyle
It is not good to be too free [Pascal]
28. God / B. Proving God / 2. Proofs of Reason / d. Pascal's Wager
Pascal knows you can't force belief, but you can make it much more probable [Pascal, by Hacking]
Pascal is right, but relies on the unsupported claim of a half as the chance of God's existence [Hacking on Pascal]
The libertine would lose a life of enjoyable sin if he chose the cloisters [Hacking on Pascal]
If you win the wager on God's existence you win everything, if you lose you lose nothing [Pascal]