Combining Texts

All the ideas for 'Leibniz: Guide for the Perplexed', 'A Priori' and 'What is Logic?'

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25 ideas

1. Philosophy / E. Nature of Metaphysics / 7. Against Metaphysics
After 1903, Husserl avoids metaphysical commitments [Mares]
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
The truth of the axioms doesn't matter for pure mathematics, but it does for applied [Mares]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
Mathematics is relations between properties we abstract from experience [Mares]
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
Substance needs independence, unity, and stability (for individuation); also it is a subject, for predicates [Perkins]
10. Modality / D. Knowledge of Modality / 2. A Priori Contingent
Light in straight lines is contingent a priori; stipulated as straight, because they happen to be so [Mares]
12. Knowledge Sources / A. A Priori Knowledge / 6. A Priori from Reason
Aristotelians dislike the idea of a priori judgements from pure reason [Mares]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Empiricists say rationalists mistake imaginative powers for modal insights [Mares]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
The most popular view is that coherent beliefs explain one another [Mares]
14. Science / B. Scientific Theories / 3. Instrumentalism
Operationalism defines concepts by our ways of measuring them [Mares]
18. Thought / D. Concepts / 2. Origin of Concepts / b. Empirical concepts
Aristotelian justification uses concepts abstracted from experience [Mares]
18. Thought / D. Concepts / 4. Structure of Concepts / c. Classical concepts
The essence of a concept is either its definition or its conceptual relations? [Mares]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
Possible worlds semantics has a nice compositional account of modal statements [Mares]
19. Language / D. Propositions / 3. Concrete Propositions
Unstructured propositions are sets of possible worlds; structured ones have components [Mares]
27. Natural Reality / C. Space / 3. Points in Space
Maybe space has points, but processes always need regions with a size [Mares]