Combining Philosophers

All the ideas for Archimedes, Kent Bach and Feferman / Feferman

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37 ideas

4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Free logic at least allows empty names, but struggles to express non-existence [Bach]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Cantor's theories needed the Axiom of Choice, but it has led to great controversy [Feferman/Feferman]
The Axiom of Choice is consistent with the other axioms of set theory [Feferman/Feferman]
The Trichotomy Principle is equivalent to the Axiom of Choice [Feferman/Feferman]
Axiom of Choice: a set exists which chooses just one element each of any set of sets [Feferman/Feferman]
Platonist will accept the Axiom of Choice, but others want criteria of selection or definition [Feferman/Feferman]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
In first-order we can't just assert existence, and it is very hard to deny something's existence [Bach]
5. Theory of Logic / E. Structures of Logic / 3. Constants in Logic
In logic constants play the role of proper names [Bach]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
Proper names can be non-referential - even predicate as well as attributive uses [Bach]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
Millian names struggle with existence, empty names, identities and attitude ascription [Bach]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / a. Descriptions
An object can be described without being referred to [Bach]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
Definite descriptions can be used to refer, but are not semantically referential [Bach]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A structure is a 'model' when the axioms are true. So which of the structures are models? [Feferman/Feferman]
Tarski and Vaught established the equivalence relations between first-order structures [Feferman/Feferman]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim-Skolem says if the sentences are countable, so is the model [Feferman/Feferman]
Löwenheim-Skolem Theorem, and Gödel's completeness of first-order logic, the earliest model theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 4. Completeness
If a sentence holds in every model of a theory, then it is logically derivable from the theory [Feferman/Feferman]
5. Theory of Logic / K. Features of Logics / 7. Decidability
'Recursion theory' concerns what can be solved by computing machines [Feferman/Feferman]
Both Principia Mathematica and Peano Arithmetic are undecidable [Feferman/Feferman]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
13. Knowledge Criteria / C. External Justification / 6. Contextual Justification / b. Invariantism
How could 'S knows he has hands' not have a fixed content? [Bach]
If contextualism is right, knowledge sentences are baffling out of their context [Bach]
Sceptics aren't changing the meaning of 'know', but claiming knowing is tougher than we think [Bach]
19. Language / B. Reference / 1. Reference theories
We can refer to fictional entities if they are abstract objects [Bach]
You 'allude to', not 'refer to', an individual if you keep their identity vague [Bach]
Fictional reference is different inside and outside the fiction [Bach]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
What refers: indefinite or definite or demonstrative descriptions, names, indexicals, demonstratives? [Bach]
If we can refer to things which change, we can't be obliged to single out their properties [Bach]
We can think of an individual without have a uniquely characterizing description [Bach]
It can't be real reference if it could refer to some other thing that satisfies the description [Bach]
Since most expressions can be used non-referentially, none of them are inherently referential [Bach]
Just alluding to or describing an object is not the same as referring to it [Bach]
19. Language / B. Reference / 5. Speaker's Reference
Context does not create reference; it is just something speakers can exploit [Bach]
'That duck' may not refer to the most obvious one in the group [Bach]
What a pronoun like 'he' refers back to is usually a matter of speaker's intentions [Bach]
Information comes from knowing who is speaking, not just from interpretation of the utterance [Bach]
19. Language / F. Communication / 5. Pragmatics / a. Contextual meaning
People slide from contextual variability all the way to contextual determination [Bach]