Combining Philosophers

All the ideas for Paul Horwich, Robert S. Wolf and Norman Malcolm

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44 ideas

2. Reason / D. Definition / 13. Against Definition
How do we determine which of the sentences containing a term comprise its definition? [Horwich]
3. Truth / A. Truth Problems / 1. Truth
The function of the truth predicate? Understanding 'true'? Meaning of 'true'? The concept of truth? A theory of truth? [Horwich]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Some correspondence theories concern facts; others are built up through reference and satisfaction [Horwich]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
The common-sense theory of correspondence has never been worked out satisfactorily [Horwich]
3. Truth / H. Deflationary Truth / 1. Redundant Truth
The redundancy theory cannot explain inferences from 'what x said is true' and 'x said p', to p [Horwich]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Truth is a useful concept for unarticulated propositions and generalisations about them [Horwich]
No deflationary conception of truth does justice to the fact that we aim for truth [Horwich]
Horwich's deflationary view is novel, because it relies on propositions rather than sentences [Horwich, by Davidson]
The deflationary picture says believing a theory true is a trivial step after believing the theory [Horwich]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
A 'tautology' must include connectives [Wolf,RS]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL
Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / d. Universal quantifier ∀
Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS]
Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS]
4. Formal Logic / C. Predicate Calculus PC / 2. Tools of Predicate Calculus / e. Existential quantifier ∃
Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / e. Axiom of the Empty Set IV
Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / n. Axiom of Comprehension
Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS]
First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Logical form is the aspects of meaning that determine logical entailments [Horwich]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Model theory reveals the structures of mathematics [Wolf,RS]
Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS]
Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS]
First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The LST Theorem is a serious limitation of first-order logic [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a theory is complete, only a more powerful language can strengthen it [Wolf,RS]
5. Theory of Logic / K. Features of Logics / 10. Monotonicity
Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Modern mathematics has unified all of its objects within set theory [Wolf,RS]
10. Modality / B. Possibility / 9. Counterfactuals
Problems with Goodman's view of counterfactuals led to a radical approach from Stalnaker and Lewis [Horwich]
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
A priori belief is not necessarily a priori justification, or a priori knowledge [Horwich]
12. Knowledge Sources / A. A Priori Knowledge / 6. A Priori from Reason
Understanding needs a priori commitment [Horwich]
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
Meaning is generated by a priori commitment to truth, not the other way around [Horwich]
12. Knowledge Sources / A. A Priori Knowledge / 9. A Priori from Concepts
Meanings and concepts cannot give a priori knowledge, because they may be unacceptable [Horwich]
If we stipulate the meaning of 'number' to make Hume's Principle true, we first need Hume's Principle [Horwich]
12. Knowledge Sources / A. A Priori Knowledge / 10. A Priori as Subjective
A priori knowledge (e.g. classical logic) may derive from the innate structure of our minds [Horwich]
14. Science / C. Induction / 6. Bayes's Theorem
Bayes' theorem explains why very surprising predictions have a higher value as evidence [Horwich]
Probability of H, given evidence E, is prob(H) x prob(E given H) / prob(E) [Horwich]
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / d. Other minds by analogy
If my conception of pain derives from me, it is a contradiction to speak of another's pain [Malcolm]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
We could know the truth-conditions of a foreign sentence without knowing its meaning [Horwich]
19. Language / D. Propositions / 1. Propositions
There are Fregean de dicto propositions, and Russellian de re propositions, or a mixture [Horwich]
19. Language / F. Communication / 6. Interpreting Language / b. Indeterminate translation
Right translation is a mapping of languages which preserves basic patterns of usage [Horwich]
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
Analyse counterfactuals using causation, not the other way around [Horwich]
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
God's existence is either necessary or impossible, and no one has shown that the concept of God is contradictory [Malcolm]