Combining Philosophers

All the ideas for Gareth Evans, Jos L. Zalabardo and William S. Jevons

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42 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
Sets can be defined by 'enumeration', or by 'abstraction' (based on a property) [Zalabardo]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
The 'Cartesian Product' of two sets relates them by pairing every element with every element [Zalabardo]
A 'partial ordering' is reflexive, antisymmetric and transitive [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Determinacy: an object is either in a set, or it isn't [Zalabardo]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / l. Axiom of Specification
Specification: Determinate totals of objects always make a set [Zalabardo]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
A first-order 'sentence' is a formula with no free variables [Zalabardo]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Γ |= φ for sentences if φ is true when all of Γ is true [Zalabardo]
Γ |= φ if φ is true when all of Γ is true, for all structures and interpretations [Zalabardo]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
Propositional logic just needs ¬, and one of ∧, ∨ and → [Zalabardo]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
We must distinguish what the speaker denotes by a name, from what the name denotes [Evans]
How can an expression be a name, if names can change their denotation? [Evans]
A private intention won't give a name a denotation; the practice needs it to be made public [Evans]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
The Causal Theory of Names is wrong, since the name 'Madagascar' actually changed denotation [Evans]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
The semantics shows how truth values depend on instantiations of properties and relations [Zalabardo]
We can do semantics by looking at given propositions, or by building new ones [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 2. Formal Truth
We make a truth assignment to T and F, which may be true and false, but merely differ from one another [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
'Logically true' (|= φ) is true for every truth-assignment [Zalabardo]
Logically true sentences are true in all structures [Zalabardo]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
A sentence-set is 'satisfiable' if at least one truth-assignment makes them all true [Zalabardo]
Some formulas are 'satisfiable' if there is a structure and interpretation that makes them true [Zalabardo]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure models a sentence if it is true in the model, and a set of sentences if they are all true in the model [Zalabardo]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
If a set is defined by induction, then proof by induction can be applied to it [Zalabardo]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
I hold that algebra and number are developments of logic [Jevons]
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
Evans argues (falsely!) that a contradiction follows from treating objects as vague [Evans, by Lowe]
Is it coherent that reality is vague, identities can be vague, and objects can have fuzzy boundaries? [Evans]
Evans assumes there can be vague identity statements, and that his proof cannot be right [Evans, by Lewis]
There clearly are vague identity statements, and Evans's argument has a false conclusion [Evans, by Lewis]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
If a=b is indeterminate, then a=/=b, and so there cannot be indeterminate identity [Evans, by Thomasson]
9. Objects / F. Identity among Objects / 6. Identity between Objects
There can't be vague identity; a and b must differ, since a, unlike b, is only vaguely the same as b [Evans, by PG]
10. Modality / B. Possibility / 5. Contingency
'Superficial' contingency: false in some world; 'Deep' contingency: no obvious verification [Evans, by Macią/Garcia-Carpentiro]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
Rigid designators can be meaningful even if empty [Evans, by Mackie,P]
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
The Homunculus Fallacy explains a subject perceiving objects by repeating the problem internally [Evans]
12. Knowledge Sources / B. Perception / 6. Inference in Perception
Experiences have no conceptual content [Evans, by Greco]
We have far fewer colour concepts than we have discriminations of colour [Evans]
18. Thought / C. Content / 1. Content
Some representational states, like perception, may be nonconceptual [Evans, by Schulte]
18. Thought / D. Concepts / 1. Concepts / a. Nature of concepts
The Generality Constraint says if you can think a predicate you can apply it to anything [Evans]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
Concepts have a 'Generality Constraint', that we must know how predicates apply to them [Evans, by Peacocke]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Speakers intend to refer to items that are the source of their information [Evans]
The intended referent of a name needs to be the cause of the speaker's information about it [Evans]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
If descriptions are sufficient for reference, then I must accept a false reference if the descriptions fit [Evans]
19. Language / F. Communication / 5. Pragmatics / b. Implicature
We use expressions 'deferentially', to conform to the use of other people [Evans]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
Charity should minimize inexplicable error, rather than maximising true beliefs [Evans]