Combining Philosophers

All the ideas for Michael Dummett, R Feldman / E Conee and Stewart Shapiro

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278 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
Philosophy aims to understand the world, through ordinary experience and science [Dummett]
1. Philosophy / F. Analytic Philosophy / 4. Conceptual Analysis
To explain a concept, we need its purpose, not just its rules of usage [Dummett]
2. Reason / A. Nature of Reason / 5. Objectivity
What matters in mathematics is its objectivity, not the existence of the objects [Dummett]
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
A contextual definition permits the elimination of the expression by a substitution [Dummett]
An 'implicit definition' gives a direct description of the relations of an entity [Shapiro]
2. Reason / E. Argument / 6. Conclusive Proof
A successful proof requires recognition of truth at every step [Dummett]
3. Truth / A. Truth Problems / 1. Truth
It is part of the concept of truth that we aim at making true statements [Dummett]
3. Truth / A. Truth Problems / 2. Defining Truth
We must be able to specify truths in a precise language, like winning moves in a game [Dummett]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
Satisfaction is 'truth in a model', which is a model of 'truth' [Shapiro]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Tarski's truth is like rules for winning games, without saying what 'winning' means [Dummett, by Davidson]
Truth is part of semantics, since valid inference preserves truth [Dummett]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
Aristotelian logic is complete [Shapiro]
4. Formal Logic / A. Syllogistic Logic / 3. Term Logic
Logic would be more natural if negation only referred to predicates [Dummett]
4. Formal Logic / B. Propositional Logic PL / 3. Truth Tables
Truth-tables are dubious in some cases, and may be a bad way to explain connective meaning [Dummett]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
It was realised that possible worlds covered all modal logics, if they had a structure [Dummett]
Modal operators are usually treated as quantifiers [Shapiro]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
Relative possibility one way may be impossible coming back, so it isn't symmetrical [Dummett]
If something is only possible relative to another possibility, the possibility relation is not transitive [Dummett]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
If possibilitiy is relative, that might make accessibility non-transitive, and T the correct system [Dummett]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
In S4 the actual world has a special place [Dummett]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Dummett says classical logic rests on meaning as truth, while intuitionist logic rests on assertability [Dummett, by Kitcher]
Mathematical statements and entities that result from an infinite process must lack a truth-value [Dummett]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / c. Basic theorems of ST
The ordered pairs <x,y> can be reduced to the class of sets of the form {{x},{x,y}} [Dummett]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / a. Types of set
A set is 'transitive' if contains every member of each of its members [Shapiro]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
ZF set theory has variables which range over sets, 'equals' and 'member', and extensionality [Dummett]
The main alternative to ZF is one which includes looser classes as well as sets [Dummett]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
To associate a cardinal with each set, we need the Axiom of Choice to find a representative [Dummett]
Choice is essential for proving downward Löwenheim-Skolem [Shapiro]
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]
The axiom of choice is controversial, but it could be replaced [Shapiro]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
Are sets part of logic, or part of mathematics? [Shapiro]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
Russell's paradox shows that there are classes which are not iterative sets [Shapiro]
It is central to the iterative conception that membership is well-founded, with no infinite descending chains [Shapiro]
Iterative sets are not Boolean; the complement of an iterative set is not an iterative sets [Shapiro]
4. Formal Logic / F. Set Theory ST / 6. Ordering in Sets
'Well-ordering' of a set is an irreflexive, transitive, and binary relation with a least element [Shapiro]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Anti-realists reject set theory [Shapiro]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Deduction is justified by the semantics of its metalanguage [Dummett, by Hanna]
Logic is the ideal for learning new propositions on the basis of others [Shapiro]
There is no 'correct' logic for natural languages [Shapiro]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Skolem and Gödel championed first-order, and Zermelo, Hilbert, and Bernays championed higher-order [Shapiro]
Bernays (1918) formulated and proved the completeness of propositional logic [Shapiro]
Can one develop set theory first, then derive numbers, or are numbers more basic? [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic was an afterthought in the development of modern logic [Shapiro]
The 'triumph' of first-order logic may be related to logicism and the Hilbert programme, which failed [Shapiro]
Maybe compactness, semantic effectiveness, and the Löwenheim-Skolem properties are desirable [Shapiro]
The notion of finitude is actually built into first-order languages [Shapiro]
First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
In classical logic, logical truths are valid formulas; in higher-order logics they are purely logical [Dummett]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic is better than set theory, since it only adds relations and operations, and nothing else [Shapiro, by Lavine]
Broad standard semantics, or Henkin semantics with a subclass, or many-sorted first-order semantics? [Shapiro]
Henkin semantics has separate variables ranging over the relations and over the functions [Shapiro]
Some say that second-order logic is mathematics, not logic [Shapiro]
In standard semantics for second-order logic, a single domain fixes the ranges for the variables [Shapiro]
Completeness, Compactness and Löwenheim-Skolem fail in second-order standard semantics [Shapiro]
If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Logical consequence can be defined in terms of the logical terminology [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]
Syntactic consequence is positive, for validity; semantic version is negative, with counterexamples [Dummett]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
If a logic is incomplete, its semantic consequence relation is not effective [Shapiro]
Semantic consequence is ineffective in second-order logic [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 / 1. Bivalence
Language can violate bivalence because of non-referring terms or ill-defined predicates [Dummett]
Undecidable statements result from quantifying over infinites, subjunctive conditionals, and the past tense [Dummett]
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]
Anti-realism needs an intuitionist logic with no law of excluded middle [Dummett, by Miller,A]
The law of excluded middle is the logical reflection of the principle of bivalence [Dummett]
Intuitionists reject excluded middle, not for a third value, but for possibility of proof [Dummett]
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Finding the logical form of a sentence is difficult, and there are no criteria of correctness [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 / 2. Logical Connectives / c. not
Natural language 'not' doesn't apply to sentences [Dummett]
Classical negation is circular, if it relies on knowing negation-conditions from truth-conditions [Dummett]
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 / F. Referring in Logic / 1. Naming / b. Names as descriptive
Ancient names like 'Obadiah' depend on tradition, not on where the name originated [Dummett]
5. Theory of Logic / G. Quantification / 1. Quantification
Classical quantification is an infinite conjunction or disjunction - but you may not know all the instances [Dummett]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
We might reduce ontology by using truth of sentences and terms, instead of using objects satisfying models [Shapiro]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
First-order logic concerns objects; second-order adds properties, kinds, relations and functions [Dummett]
Second-order variables also range over properties, sets, relations or functions [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 / 1. Semantics of Logic
Beth trees show semantics for intuitionistic logic, in terms of how truth has been established [Dummett]
In standard views you could replace 'true' and 'false' with mere 0 and 1 [Dummett]
Classical two-valued semantics implies that meaning is grasped through truth-conditions [Dummett]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths and inference are characterized either syntactically or semantically [Dummett]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
'Satisfaction' is a function from models, assignments, and formulas to {true,false} [Shapiro]
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]
Semantics for models uses set-theory [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]
Categoricity can't be reached in a first-order language [Shapiro]
The set-theoretical hierarchy contains as many isomorphism types as possible [Shapiro]
An axiomatization is 'categorical' if its models are isomorphic, so there is really only one interpretation [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
The Löwenheim-Skolem theorems show an explosion of infinite models, so 1st-order is useless for infinity [Shapiro]
Substitutional semantics only has countably many terms, so Upward Löwenheim-Skolem trivially fails [Shapiro]
Any theory with an infinite model has a model of every infinite cardinality [Shapiro]
Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
Downward Löwenheim-Skolem: each satisfiable countable set always has countable models [Shapiro]
Upward Löwenheim-Skolem: each infinite model has infinite models of all sizes [Shapiro]
The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
5. Theory of Logic / K. Features of Logics / 3. Soundness
'Weakly sound' if every theorem is a logical truth; 'sound' if every deduction is a semantic consequence [Shapiro]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Soundness and completeness proofs test the theory of meaning, rather than the logic theory [Dummett]
We can live well without completeness in logic [Shapiro]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Non-compactness is a strength of second-order logic, enabling characterisation of infinite structures [Shapiro]
Compactness is derived from soundness and completeness [Shapiro]
5. Theory of Logic / K. Features of Logics / 9. Expressibility
A language is 'semantically effective' if its logical truths are recursively enumerable [Shapiro]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / b. The Heap paradox ('Sorites')
Surely there is no exact single grain that brings a heap into existence [Dummett]
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 / b. Types of number
A prime number is one which is measured by a unit alone [Dummett]
Complex numbers can be defined as reals, which are defined as rationals, then integers, then naturals [Shapiro]
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / c. Priority of numbers
Addition of quantities is prior to ordering, as shown in cyclic domains like angles [Dummett]
Ordinals seem more basic than cardinals, since we count objects in sequence [Dummett]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / d. Natural numbers
Only higher-order languages can specify that 0,1,2,... are all the natural numbers that there are [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
Natural numbers are the finite ordinals, and integers are equivalence classes of pairs of finite ordinals [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 / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [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
A number is a multitude composed of units [Dummett]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
We understand 'there are as many nuts as apples' as easily by pairing them as by counting them [Dummett]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / c. Potential infinite
Platonists ruin infinity, which is precisely a growing structure which is never completed [Dummett]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
The 'continuum' is the cardinality of the powerset of a denumerably infinite set [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
There is no grounding for mathematics that is more secure than mathematics [Shapiro]
Categories are the best foundation for 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
First-order arithmetic can't even represent basic number theory [Shapiro]
Natural numbers just need an initial object, successors, and an induction principle [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Intuitionists find the Incompleteness Theorem unsurprising, since proof is intuitive, not formal [Dummett]
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 / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Some sets of natural numbers are definable in set-theory but not in 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]
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [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
The identity of a number may be fixed by something outside structure - by counting [Dummett]
Numbers aren't fixed by position in a structure; it won't tell you whether to start with 0 or 1 [Dummett]
The number 4 has different positions in the naturals and the wholes, with the same structure [Dummett]
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 / c. Neo-logicism
Logicism is distinctive in seeking a universal language, and denying that logic is a series of abstractions [Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Mathematics and logic have no border, and logic must involve mathematics and its ontology [Shapiro]
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
Set theory isn't part of logic, and why reduce to something more complex? [Dummett]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / a. Constructivism
For intuitionists it is constructed proofs (which take time) which make statements true [Dummett]
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 / b. Intuitionism
Intuitionism says that totality of numbers is only potential, but is still determinate [Dummett]
Intuitionists rely on the proof of mathematical statements, not their truth [Dummett]
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
Some reject formal properties if they are not defined, or defined impredicatively [Shapiro]
'Impredicative' definitions refer to the thing being described [Shapiro]
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 / B. Change in Existence / 1. Nature of Change
A 'Cambridge Change' is like saying 'the landscape changes as you travel east' [Dummett]
7. Existence / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
We can't say that light is concrete but radio waves abstract [Dummett]
Ostension is possible for concreta; abstracta can only be referred to via other objects [Dummett, by Hale]
The concrete/abstract distinction seems crude: in which category is the Mistral? [Dummett]
We don't need a sharp concrete/abstract distinction [Dummett]
The distinction of concrete/abstract, or actual/non-actual, is a scale, not a dichotomy [Dummett]
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 / 2. Realism
Dummett saw realism as acceptance of bivalence, rather than of mind-independent entities [Dummett, by Potter]
Realism is just the application of two-valued semantics to sentences [Dummett]
Metaphysical realists are committed to all unambiguous statements being true or not true [Dummett]
Philosophers should not presume reality, but only invoke it when language requires it [Dummett]
7. Existence / D. Theories of Reality / 4. Anti-realism
For anti-realists there are no natural distinctions between objects [Dummett, by Benardete,JA]
We can't make sense of a world not apprehended by a mind [Dummett]
I no longer think what a statement about the past says is just what can justify it [Dummett]
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 / 8. Facts / b. Types of fact
Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts [Dummett]
7. Existence / D. Theories of Reality / 8. Facts / c. Facts and truths
We know we can state facts, with true statements [Dummett]
7. Existence / D. Theories of Reality / 10. Vagueness / b. Vagueness of reality
To say reality itself is vague is not properly intelligible [Dummett]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
'That is red or orange' might be considered true, even though 'that is red' and 'that is orange' were not [Dummett]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / a. Ontological commitment
The context principle for names rules out a special philosophical sense for 'existence' [Dummett]
The objects we recognise the world as containing depends on the structure of our language [Dummett]
8. Modes of Existence / B. Properties / 10. Properties as Predicates
Properties are often seen as intensional; equiangular and equilateral are different, despite identity of objects [Shapiro]
8. Modes of Existence / B. Properties / 11. Properties as Sets
Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
8. Modes of Existence / D. Universals / 1. Universals
We can understand universals by studying predication [Dummett]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
'Nominalism' used to mean denial of universals, but now means denial of abstract objects [Dummett]
Nominalism assumes unmediated mental contact with objects [Dummett]
9. Objects / A. Existence of Objects / 1. Physical Objects
Concrete objects such as sounds and smells may not be possible objects of ostension [Dummett]
The notion of 'object' is at least partially structural and mathematical [Shapiro]
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
Abstract objects may not cause changes, but they can be the subject of change [Dummett]
The existence of abstract objects is a pseudo-problem [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
If we can intuitively apprehend abstract objects, this makes them observable and causally active [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Abstract objects nowadays are those which are objective but not actual [Dummett]
Abstract objects must have names that fall within the range of some functional expression [Dummett]
It is absurd to deny the Equator, on the grounds that it lacks causal powers [Dummett]
'We've crossed the Equator' has truth-conditions, so accept the Equator - and it's an object [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / d. Problems with abstracta
If a genuine singular term needs a criterion of identity, we must exclude abstract nouns [Dummett, by Hale]
Abstract objects can never be confronted, and need verbal phrases for reference [Dummett]
Abstract objects need the context principle, since they can't be encountered directly [Dummett]
9. Objects / A. Existence of Objects / 3. Objects in Thought
There is a modern philosophical notion of 'object', first introduced by Frege [Dummett]
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 / 2. Defining Identity
Content is replaceable if identical, so replaceability can't define identity [Dummett, by Dummett]
Frege introduced criteria for identity, but thought defining identity was circular [Dummett]
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
Possible worlds aren't how the world might be, but how a world might be, given some possibility [Dummett]
Why does the 'myth' of possible worlds produce correct modal logic? [Shapiro]
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
If possible worlds have no structure (S5) they are equal, and it is hard to deny them reality [Dummett]
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
Involuntary beliefs can still be evaluated [Feldman/Conee]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
The existence of a universe without sentience or intelligence is an unintelligible fantasy [Dummett]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Empirical and a priori knowledge are not distinct, but are extremes of a sliding scale [Dummett]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / b. Evidentialism
Evidentialism is the view that justification is determined by the quality of the evidence [Feldman/Conee]
Beliefs should fit evidence, and if you ought to believe it, then you are justified [Feldman/Conee]
13. Knowledge Criteria / C. External Justification / 3. Reliabilism / a. Reliable knowledge
If someone rejects good criticism through arrogance, that is irrelevant to whether they have knowledge [Feldman/Conee]
14. Science / D. Explanation / 2. Types of Explanation / a. Types of explanation
An explanation is often a deduction, but that may well beg the question [Dummett]
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
We apprehend small, finite mathematical structures by abstraction from patterns [Shapiro]
18. Thought / A. Modes of Thought / 1. Thought
The theories of meaning and understanding are the only routes to an account of thought [Dummett]
A theory of thought will include propositional attitudes as well as propositions [Dummett]
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
Concepts only have a 'functional character', because they map to truth values, not objects [Dummett, by Davidson]
18. Thought / D. Concepts / 4. Structure of Concepts / i. Conceptual priority
Maybe a concept is 'prior' to another if it can be defined without the second concept [Dummett]
An argument for conceptual priority is greater simplicity in explanation [Dummett]
18. Thought / E. Abstraction / 1. Abstract Thought
You can't infer a dog's abstract concepts from its behaviour [Dummett]
Abstract terms are acceptable as long as we know how they function linguistically [Dummett]
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
A structure is an abstraction, focussing on relationships, and ignoring other features [Shapiro]
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
Since abstract objects cannot be picked out, we must rely on identity statements [Dummett]
There is no reason why abstraction by equivalence classes should be called 'logical' [Dummett, by Tait]
We arrive at the concept 'suicide' by comparing 'Cato killed Cato' with 'Brutus killed Brutus' [Dummett]
Abstract objects might come by abstraction over an equivalence class of base entities [Shapiro]
18. Thought / E. Abstraction / 8. Abstractionism Critique
To abstract from spoons (to get the same number as the forks), the spoons must be indistinguishable too [Dummett]
To 'abstract from' is a logical process, as opposed to the old mental view [Dummett]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
Stating a sentence's truth-conditions is just paraphrasing the sentence [Dummett]
If a sentence is effectively undecidable, we can never know its truth conditions [Dummett]
To know the truth-conditions of a sentence, you must already know the meaning [Dummett]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
Verification is not an individual but a collective activity [Dummett]
A justificationist theory of meaning leads to the rejection of classical logic [Dummett]
Verificationism could be realist, if we imagined the verification by a superhuman power [Dummett]
If truths about the past depend on memories and current evidence, the past will change [Dummett]
19. Language / A. Nature of Meaning / 6. Meaning as Use
Meaning as use puts use beyond criticism, and needs a holistic view of language [Dummett]
We could only guess the meanings of 'true' and 'false' when sentences were used [Dummett]
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Sentences are the primary semantic units, because they can say something [Dummett]
19. Language / A. Nature of Meaning / 10. Denial of Meanings
Holism is not a theory of meaning; it is the denial that a theory of meaning is possible [Dummett]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
A realistic view of reference is possible for concrete objects, but not for abstract objects [Dummett, by Hale]
The causal theory of reference can't distinguish just hearing a name from knowing its use [Dummett]
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Fregean semantics assumes a domain articulated into individual objects [Dummett]
19. Language / C. Assigning Meanings / 6. Truth-Conditions Semantics
Truth-condition theorists must argue use can only be described by appeal to conditions of truth [Dummett]
The truth-conditions theory must get agreement on a conception of truth [Dummett]
19. Language / D. Propositions / 1. Propositions
We can't distinguish a proposition from its content [Dummett]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / d. Virtue theory critique
To explain generosity in a person, you must understand a generous action [Dummett]
26. Natural Theory / B. Natural Kinds / 7. Critique of Kinds
Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett]
27. Natural Reality / C. Space / 3. Points in Space
Why should the limit of measurement be points, not intervals? [Dummett]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is the measure of change, so we can't speak of time before all change [Dummett]
27. Natural Reality / D. Time / 1. Nature of Time / f. Eternalism
Maybe past (which affects us) and future (which we can affect) are both real [Dummett]
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
If Presentism is correct, we cannot even say that the present changes [Dummett]
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
The present cannot exist alone as a mere boundary; past and future truths are rendered meaningless [Dummett]