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All the ideas for 'Mathematical logic and theory of types', 'Truth and Truthmakers' and 'Philosophy of Mathematics'

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104 ideas

1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
All metaphysical discussion should be guided by a quest for truthmakers [Armstrong]
2. Reason / A. Nature of Reason / 6. Coherence
Coherence is a primitive, intuitive notion, not reduced to something formal [Shapiro]
2. Reason / D. Definition / 7. Contextual Definition
An 'implicit definition' gives a direct description of the relations of an entity [Shapiro]
3. Truth / B. Truthmakers / 4. Truthmaker Necessitarianism
Truth-making can't be entailment, because truthmakers are portions of reality [Armstrong]
Armstrong says truthmakers necessitate their truth, where 'necessitate' is a primitive relation [Armstrong, by MacBride]
3. Truth / B. Truthmakers / 6. Making Negative Truths
Negative truths have as truthmakers all states of affairs relevant to the truth [Armstrong]
The nature of arctic animals is truthmaker for the absence of penguins there [Armstrong]
3. Truth / B. Truthmakers / 7. Making Modal Truths
One truthmaker will do for a contingent truth and for its contradictory [Armstrong]
In mathematics, truthmakers are possible instantiations of structures [Armstrong]
The truthmakers for possible unicorns are the elements in their combination [Armstrong]
What is the truthmaker for 'it is possible that there could have been nothing'? [Armstrong]
3. Truth / B. Truthmakers / 8. Making General Truths
Necessitating general truthmakers must also specify their limits [Armstrong]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
Modal operators are usually treated as quantifiers [Shapiro]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
The set theory brackets { } assert that the member is a unit [Armstrong]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
For 'there is a class with no members' we don't need the null set as truthmaker [Armstrong]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Axiom of Choice: some function has a value for every set in a given set [Shapiro]
The Axiom of Choice seems to license an infinite amount of choosing [Shapiro]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Classes can be reduced to propositional functions [Russell, by Hanna]
Anti-realists reject set theory [Shapiro]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
The two standard explanations of consequence are semantic (in models) and deductive [Shapiro]
5. Theory of Logic / B. Logical Consequence / 5. Modus Ponens
Intuitionism only sanctions modus ponens if all three components are proved [Shapiro]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Either logic determines objects, or objects determine logic, or they are separate [Shapiro]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
The law of excluded middle might be seen as a principle of omniscience [Shapiro]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Classical connectives differ from their ordinary language counterparts; '∧' is timeless, unlike 'and' [Shapiro]
5. Theory of Logic / E. Structures of Logic / 5. Functions in Logic
A function is just an arbitrary correspondence between collections [Shapiro]
5. Theory of Logic / G. Quantification / 6. Plural Quantification
Maybe plural quantifiers should be understood in terms of classes or sets [Shapiro]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
A sentence is 'satisfiable' if it has a model [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Model theory deals with relations, reference and extensions [Shapiro]
The central notion of model theory is the relation of 'satisfaction' [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
Theory ontology is never complete, but is only determined 'up to isomorphism' [Shapiro]
The set-theoretical hierarchy contains as many isomorphism types as possible [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Any theory with an infinite model has a model of every infinite cardinality [Shapiro]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / d. Russell's paradox
The class of classes which lack self-membership leads to a contradiction [Russell, by Grayling]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Virtually all of mathematics can be modeled in set theory [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers are thought of as either Cauchy sequences or Dedekind cuts [Shapiro]
Understanding the real-number structure is knowing usage of the axiomatic language of analysis [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / i. Reals from cuts
Cuts are made by the smallest upper or largest lower number, some of them not rational [Shapiro]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
Classes have cardinalities, so their members must all be treated as units [Armstrong]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
There is no grounding for mathematics that is more secure than mathematics [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
For intuitionists, proof is inherently informal [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
Natural numbers just need an initial object, successors, and an induction principle [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / b. Greek arithmetic
Mathematics originally concerned the continuous (geometry) and the discrete (arithmetic) [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Mathematical foundations may not be sets; categories are a popular rival [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Baseball positions and chess pieces depend entirely on context [Shapiro]
The even numbers have the natural-number structure, with 6 playing the role of 3 [Shapiro]
Could infinite structures be apprehended by pattern recognition? [Shapiro]
The 4-pattern is the structure common to all collections of four objects [Shapiro]
The main mathematical structures are algebraic, ordered, and topological [Shapiro]
Some structures are exemplified by both abstract and concrete [Shapiro]
Mathematical structures are defined by axioms, or in set theory [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / b. Varieties of structuralism
The main versions of structuralism are all definitionally equivalent [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
Is there is no more to structures than the systems that exemplify them? [Shapiro]
Number statements are generalizations about number sequences, and are bound variables [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / d. Platonist structuralism
Because one structure exemplifies several systems, a structure is a one-over-many [Shapiro]
There is no 'structure of all structures', just as there is no set of all sets [Shapiro]
Shapiro's structuralism says model theory (comparing structures) is the essence of mathematics [Shapiro, by Friend]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
Does someone using small numbers really need to know the infinite structure of arithmetic? [Shapiro]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
We distinguish realism 'in ontology' (for objects), and 'in truth-value' (for being either true or false) [Shapiro]
If mathematical objects are accepted, then a number of standard principles will follow [Shapiro]
Platonists claim we can state the essence of a number without reference to the others [Shapiro]
Platonism must accept that the Peano Axioms could all be false [Shapiro]
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Intuition is an outright hindrance to five-dimensional geometry [Shapiro]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
A stone is a position in some pattern, and can be viewed as an object, or as a location [Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Type theory seems an extreme reaction, since self-exemplification is often innocuous [Swoyer on Russell]
Russell's improvements blocked mathematics as well as paradoxes, and needed further axioms [Russell, by Musgrave]
Type theory means that features shared by different levels cannot be expressed [Morris,M on Russell]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Ramified types can be defended as a system of intensional logic, with a 'no class' view of sets [Russell, by Linsky,B]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
Can the ideal constructor also destroy objects? [Shapiro]
Presumably nothing can block a possible dynamic operation? [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
A set does not exist unless at least one of its specifications is predicative [Russell, by Bostock]
Russell is a conceptualist here, saying some abstracta only exist because definitions create them [Russell, by Bostock]
Vicious Circle says if it is expressed using the whole collection, it can't be in the collection [Russell, by Bostock]
7. Existence / A. Nature of Existence / 1. Nature of Existence
Can we discover whether a deck is fifty-two cards, or a person is time-slices or molecules? [Shapiro]
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
Logical atomism builds on the simple properties, but are they the only possible properties? [Armstrong]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The abstract/concrete boundary now seems blurred, and would need a defence [Shapiro]
Mathematicians regard arithmetic as concrete, and group theory as abstract [Shapiro]
7. Existence / D. Theories of Reality / 5. Naturalism
'Naturalism' says only the world of space-time exists [Armstrong]
7. Existence / D. Theories of Reality / 7. Fictionalism
Fictionalism eschews the abstract, but it still needs the possible (without model theory) [Shapiro]
Structuralism blurs the distinction between mathematical and ordinary objects [Shapiro]
7. Existence / D. Theories of Reality / 9. States of Affairs
Truthmaking needs states of affairs, to unite particulars with tropes or universals. [Armstrong]
8. Modes of Existence / B. Properties / 2. Need for Properties
We need properties, as minimal truthmakers for the truths about objects [Armstrong]
8. Modes of Existence / B. Properties / 3. Types of Properties
The determinates of a determinable must be incompatible with each other [Armstrong]
Length is a 'determinable' property, and one mile is one its 'determinates' [Armstrong]
8. Modes of Existence / B. Properties / 13. Tropes / a. Nature of tropes
If tropes are non-transferable, then they necessarily belong to their particular substance [Armstrong]
8. Modes of Existence / C. Powers and Dispositions / 5. Powers and Properties
Properties are not powers - they just have powers [Armstrong]
8. Modes of Existence / C. Powers and Dispositions / 7. Against Powers
Powers must result in some non-powers, or there would only be potential without result [Armstrong]
How does the power of gravity know the distance it acts over? [Armstrong]
8. Modes of Existence / E. Nominalism / 5. Class Nominalism
The class of similar things is much too big a truthmaker for the feature of a particular [Armstrong]
9. Objects / A. Existence of Objects / 1. Physical Objects
The notion of 'object' is at least partially structural and mathematical [Shapiro]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
A blurry border is still a border [Shapiro]
9. Objects / F. Identity among Objects / 1. Concept of Identity
When entities contain entities, or overlap with them, there is 'partial' identity [Armstrong]
10. Modality / A. Necessity / 6. Logical Necessity
Logical modalities may be acceptable, because they are reducible to satisfaction in models [Shapiro]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Why does the 'myth' of possible worlds produce correct modal logic? [Shapiro]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds don't fix necessities; intrinsic necessities imply the extension in worlds [Armstrong]
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
We apprehend small, finite mathematical structures by abstraction from patterns [Shapiro]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
General truths are a type of negative truth, saying there are no more ravens than black ones [Armstrong]
18. Thought / E. Abstraction / 2. Abstracta by Selection
Simple types can be apprehended through their tokens, via abstraction [Shapiro]
18. Thought / E. Abstraction / 3. Abstracta by Ignoring
We can apprehend structures by focusing on or ignoring features of patterns [Shapiro]
We can focus on relations between objects (like baseballers), ignoring their other features [Shapiro]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
Abstract objects might come by abstraction over an equivalence class of base entities [Shapiro]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
For all being, there is a potential proposition which expresses its existence and nature [Armstrong]
A realm of abstract propositions is causally inert, so has no explanatory value [Armstrong]
26. Natural Theory / C. Causation / 4. Naturalised causation
Negative causations supervene on positive causations plus their laws? [Armstrong]
27. Natural Reality / D. Time / 3. Parts of Time / e. Present moment
The pure present moment is too brief to be experienced [Armstrong]