Combining Philosophers

All the ideas for Hermarchus, Stewart Shapiro and Ludwig Wittgenstein

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362 ideas

1. Philosophy / A. Wisdom / 2. Wise People
If you hope to improve the world, all you can do is improve yourself [Wittgenstein]
While faith is a passion (as Kierkegaard says), wisdom is passionless [Wittgenstein]
1. Philosophy / C. History of Philosophy / 1. History of Philosophy
The history of philosophy only matters if the subject is a choice between rival theories [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 1. Philosophy
What we cannot speak about we must pass over in silence [Wittgenstein]
A philosopher is outside any community of ideas [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
Philosophy is a battle against the bewitchment of our intelligence by means of language [Wittgenstein]
The main problem of philosophy is what can and cannot be thought and expressed [Wittgenstein, by Grayling]
I say (contrary to Wittgenstein) that philosophy expresses what we thought we must be silent about [Ansell Pearson on Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / d. Philosophy as puzzles
Philosophy tries to be rid of certain intellectual puzzles, irrelevant to daily life [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 6. Hopes for Philosophy
If a question can be framed at all, it is also possible to answer it [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
The 'Tractatus' is a masterpiece of anti-philosophy [Badiou on Wittgenstein]
This work solves all the main problems, but that has little value [Wittgenstein]
Once you understand my book you will see that it is nonsensical [Wittgenstein]
Philosophers express puzzlement, but don't clearly state the puzzle [Wittgenstein]
What is your aim in philosophy? - To show the fly the way out of the fly-bottle [Wittgenstein]
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
The limits of my language means the limits of my world [Wittgenstein]
Analysis complicates a statement, but only as far as the complexity of its meaning [Wittgenstein]
All complex statements can be resolved into constituents and descriptions [Wittgenstein]
Our language is an aspect of biology, and so its inner logic is opaque [Wittgenstein]
Most philosophical questions arise from failing to understand the logic of language [Wittgenstein]
We don't need a theory of truth, because we use the word perfectly well [Wittgenstein]
Bring words back from metaphysics to everyday use [Wittgenstein]
1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
We already know what we want to know, and analysis gives us no new facts [Wittgenstein]
This book says we should either say it clearly, or shut up [Wittgenstein]
1. Philosophy / G. Scientific Philosophy / 3. Scientism
Science is all the true propositions [Wittgenstein]
2. Reason / A. Nature of Reason / 6. Coherence
Coherence is a primitive, intuitive notion, not reduced to something formal [Shapiro]
2. Reason / B. Laws of Thought / 3. Non-Contradiction
The problem is to explain the role of contradiction in social life [Wittgenstein]
2. Reason / B. Laws of Thought / 6. Ockham's Razor
If a sign is useless it is meaningless; that is the point of Ockham's maxim [Wittgenstein]
2. Reason / D. Definition / 7. Contextual Definition
An 'implicit definition' gives a direct description of the relations of an entity [Shapiro]
2. Reason / F. Fallacies / 8. Category Mistake / a. Category mistakes
Words of the same kind can be substituted in a proposition without producing nonsense [Wittgenstein]
2. Reason / F. Fallacies / 8. Category Mistake / b. Category mistake as syntactic
Talking nonsense is not following the rules [Wittgenstein]
Grammar says that saying 'sound is red' is not false, but nonsense [Wittgenstein]
3. Truth / A. Truth Problems / 2. Defining Truth
There is no theory of truth, because it isn't a concept [Wittgenstein]
3. Truth / B. Truthmakers / 2. Truthmaker Relation
The best account of truth-making is isomorphism [Wittgenstein, by Mulligan/Simons/Smith]
3. Truth / B. Truthmakers / 5. What Makes Truths / c. States of affairs make truths
He says the world is the facts because it is the facts which fix all the truths [Wittgenstein, by Morris,M]
3. Truth / B. Truthmakers / 11. Truthmaking and Correspondence
All truths have truth-makers, but only atomic truths correspond to them [Wittgenstein, by Rami]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Wittgenstein's picture theory is the best version of the correspondence theory of truth [Read on Wittgenstein]
Language is [propositions-elementary propositions-names]; reality is [facts-states of affairs-objects] [Wittgenstein, by Grayling]
The account of truth in the 'Tractatus' seems a perfect example of the correspondence theory [Wittgenstein, by O'Grady]
Pictures reach out to or feel reality, touching at the edges, correlating in its parts [Wittgenstein]
All thought has the logical form of reality [Wittgenstein]
3. Truth / C. Correspondence Truth / 2. Correspondence to Facts
Proposition elements correlate with objects, but the whole picture does not correspond to a fact [Wittgenstein, by Morris,M]
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 / H. Deflationary Truth / 1. Redundant Truth
'It is true that this follows' means simply: this follows [Wittgenstein]
4. Formal Logic / A. Syllogistic Logic / 1. Aristotelian Logic
Aristotelian logic is complete [Shapiro]
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 / 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 / j. Axiom of Choice IX
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
It is central to the iterative conception that membership is well-founded, with no infinite descending chains [Shapiro]
Russell's paradox shows that there are classes which are not iterative sets [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
Logic fills the world, to its limits [Wittgenstein]
In logic nothing is hidden [Wittgenstein]
We can dispense with self-evidence, if language itself prevents logical mistakes [Jeshion on Wittgenstein]
Logic concerns everything that is subject to law; the rest is accident [Wittgenstein]
There is no 'correct' logic for natural languages [Shapiro]
Logic is the ideal for learning new propositions on the basis of others [Shapiro]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
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]
Skolem and Gödel championed first-order, and Zermelo, Hilbert, and Bernays championed higher-order [Shapiro]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Wittgenstein is right that logic is just tautologies [Wittgenstein, by Russell]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Logic is a priori because it is impossible to think illogically [Wittgenstein]
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 / 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]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
If q implies p, that is justified by q and p, not by some 'laws' of inference [Wittgenstein]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Semantic consequence is ineffective in second-order logic [Shapiro]
If a logic is incomplete, its semantic consequence relation is not effective [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]
The propositions of logic are analytic tautologies [Wittgenstein]
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Wittgenstein convinced Russell that logic is tautologies, not Platonic forms [Wittgenstein, by Monk]
5. Theory of Logic / C. Ontology of Logic / 4. Logic by Convention
Laws of logic are like laws of chess - if you change them, it's just a different game [Wittgenstein]
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]
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Two colours in the same place is ruled out by the logical structure of colour [Wittgenstein]
Contradiction is between two rules, not between rule and reality [Wittgenstein]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
The sign of identity is not allowed in 'Tractatus' [Wittgenstein, by Bostock]
The identity sign is not essential in logical notation, if every sign has a different meaning [Wittgenstein, by Ramsey]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
A statement's logical form derives entirely from its constituents [Wittgenstein]
Wittgenstein says we want the grammar of problems, not their first-order logical structure [Wittgenstein, by Horsten/Pettigrew]
Finding the logical form of a sentence is difficult, and there are no criteria of correctness [Shapiro]
Apparent logical form may not be real logical form [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
My fundamental idea is that the 'logical constants' do not represent [Wittgenstein]
'And' and 'not' are non-referring terms, which do not represent anything [Wittgenstein, by Fogelin]
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
'Not' isn't an object, because not-not-p would then differ from p [Wittgenstein]
We may correctly use 'not' without making the rule explicit [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / d. and
Saying 'and' has meaning is just saying it works in a sentence [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
'Object' is a pseudo-concept, properly indicated in logic by the variable x [Wittgenstein]
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 / a. Names
Names are primitive, and cannot be analysed [Wittgenstein]
A person's name doesn't mean their body; bodies don't sit down, and their existence can be denied [Wittgenstein]
Naming is a preparation for description [Wittgenstein]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
A name is not determined by a description, but by a cluster or family [Wittgenstein, by Kripke]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
A name is primitive, and its meaning is the object [Wittgenstein]
5. Theory of Logic / G. Quantification / 1. Quantification
Wittgenstein tried unsuccessfully to reduce quantifiers to conjunctions and disjunctions [Wittgenstein, by Jacquette]
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
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 / H. Proof Systems / 1. Proof Systems
Logical proof just explicates complicated tautologies [Wittgenstein]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths are just 'by-products' of the introduction rules for logical constants [Wittgenstein, by Hacking]
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
Semantics for models uses set-theory [Shapiro]
The central notion of model theory is the relation of 'satisfaction' [Shapiro]
Model theory deals with relations, reference and extensions [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
An axiomatization is 'categorical' if its models are isomorphic, so there is really only one interpretation [Shapiro]
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]
Categoricity can't be reached in a first-order language [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
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]
Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [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]
The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
Downward Löwenheim-Skolem: each satisfiable countable set always has countable models [Shapiro]
Any theory with an infinite model has a model of every infinite cardinality [Shapiro]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Logic doesn't split into primitive and derived propositions; they all have the same status [Wittgenstein]
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
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 / a. The Liar paradox
'This sentence is false' sends us in a looping search for its proposition [Wittgenstein, by Fogelin]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
In mathematics everything is algorithm and nothing is meaning [Wittgenstein]
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
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 / 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
We don't get 'nearer' to something by adding decimals to 1.1412... (root-2) [Wittgenstein]
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 / 5. The Infinite / a. The Infinite
Infinity is not a number, so doesn't say how many; it is the property of a law [Wittgenstein]
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 / 5. Definitions of Number / a. Defining numbers
A number is a repeated operation [Wittgenstein]
The concept of number is just what all numbers have in common [Wittgenstein]
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
The theory of classes is superfluous in mathematics [Wittgenstein]
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
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 / a. Early logicism
Two and one making three has the necessity of logical inference [Wittgenstein]
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]
Wittgenstein hated logicism, and described it as a cancerous growth [Wittgenstein, by Monk]
The logic of the world is shown by tautologies in logic, and by equations in mathematics [Wittgenstein]
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
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
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
The world is facts, not things. Facts determine the world, and the world divides into facts [Wittgenstein]
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
Atomic facts correspond to true elementary propositions [Wittgenstein]
The sense of propositions relies on the world's basic logical structure [Wittgenstein]
The 'Tractatus' is an extreme example of 'Logical Atomism' [Wittgenstein, by Grayling]
In atomic facts the objects hang together like chain links [Wittgenstein]
The structure of an atomic fact is how its objects combine; this possibility is its form [Wittgenstein]
If a proposition is elementary, no other elementary proposition contradicts it [Wittgenstein]
Analysis must end in elementary propositions, which are combinations of names [Wittgenstein]
Nothing can be inferred from an elementary proposition [Wittgenstein]
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 / 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 / a. Facts
Do his existent facts constitute the world, or determine the world? [Morris,M on Wittgenstein]
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
There are no positive or negative facts; these are just the forms of propositions [Wittgenstein]
7. Existence / D. Theories of Reality / 8. Facts / d. Negative facts
Facts can be both positive and negative [Wittgenstein, by Potter]
The world is determined by the facts, and there are no further facts [Wittgenstein]
The existence of atomic facts is a positive fact, their non-existence a negative fact [Wittgenstein]
On white paper a black spot is a positive fact and a white spot a negative fact [Wittgenstein]
8. Modes of Existence / A. Relations / 2. Internal Relations
The order of numbers is an internal relation, not an external one [Wittgenstein]
A relation is internal if it is unthinkable that its object should not possess it [Wittgenstein]
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 / 5. Universals as Concepts
Using 'green' is a commitment to future usage of 'green' [Wittgenstein]
9. Objects / A. Existence of Objects / 1. Physical Objects
The notion of 'object' is at least partially structural and mathematical [Shapiro]
Objects are the substance of the world [Wittgenstein]
9. Objects / A. Existence of Objects / 3. Objects in Thought
An 'object' is just what can be referred to without possible non-existence [Wittgenstein]
9. Objects / A. Existence of Objects / 5. Simples
Objects are simple [Wittgenstein]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Apart from the facts, there is only substance [Wittgenstein]
9. Objects / B. Unity of Objects / 2. Substance / b. Need for substance
We accept substance, to avoid infinite backwards chains of meaning [Wittgenstein, by Potter]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
A blurry border is still a border [Shapiro]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Essence is expressed by grammar [Wittgenstein]
9. Objects / D. Essence of Objects / 9. Essence and Properties
To know an object we must know the form and content of its internal properties [Wittgenstein, by Potter]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity is not a relation between objects [Wittgenstein]
9. Objects / F. Identity among Objects / 2. Defining Identity
You can't define identity by same predicates, because two objects with same predicates is assertable [Wittgenstein]
9. Objects / F. Identity among Objects / 5. Self-Identity
Two things can't be identical, and self-identity is an empty concept [Wittgenstein]
10. Modality / A. Necessity / 3. Types of Necessity
The only necessity is logical necessity [Wittgenstein]
10. Modality / A. Necessity / 6. Logical Necessity
Logical modalities may be acceptable, because they are reducible to satisfaction in models [Shapiro]
10. Modality / C. Sources of Modality / 3. Necessity by Convention
For each necessity in the world there is an arbitrary rule of language [Wittgenstein]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
The tautologies of logic show the logic of language and the world [Wittgenstein]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
What is thinkable is possible [Wittgenstein]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Each thing is in a space of possible facts [Wittgenstein]
Why does the 'myth' of possible worlds produce correct modal logic? [Shapiro]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Unlike the modern view of a set of worlds, Wittgenstein thinks of a structured manifold of them [Wittgenstein, by White,RM]
An imagined world must have something in common with the real world [Wittgenstein]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
To know an object you must know all its possible occurrences [Wittgenstein]
The 'form' of an object is its possible roles in facts [Wittgenstein]
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Two objects may only differ in being different [Wittgenstein]
11. Knowledge Aims / A. Knowledge / 2. Understanding
Understanding is translation, into action or into other symbols [Wittgenstein]
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
The belief that fire burns is like the fear that it burns [Wittgenstein]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Are sense-data the material of which the universe is made? [Wittgenstein]
11. Knowledge Aims / C. Knowing Reality / 4. Solipsism
Strict solipsism is pure realism, with the self as a mere point in surrounding reality [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
If the truth doesn't follow from self-evidence, then self-evidence cannot justify a truth [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
My main problem is the order of the world, and whether it is knowable a priori [Wittgenstein]
The Tractatus aims to reveal the necessities, without appealing to synthetic a priori truths [Wittgenstein, by Morris,M]
There is no a priori order of things [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
Logic and maths can't say anything about the world, since, as tautologies, they are consistent with all realities [Wittgenstein, by Grayling]
12. Knowledge Sources / A. A Priori Knowledge / 10. A Priori as Subjective
Logic is a priori because we cannot think illogically [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 11. Denying the A Priori
No pictures are true a priori [Wittgenstein]
12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory
We live in sense-data, but talk about physical objects [Wittgenstein]
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Part of what we mean by stating the facts is the way we tend to experience them [Wittgenstein]
As sense-data are necessarily private, they are attacked by Wittgenstein's objections [Wittgenstein, by Robinson,H]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
12. Knowledge Sources / E. Direct Knowledge / 2. Intuition
How do I decide when to accept or obey an intuition? [Wittgenstein]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
If you remember wrongly, then there must be some other criterion than your remembering [Wittgenstein]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
Foundations need not precede other beliefs [Wittgenstein]
13. Knowledge Criteria / C. External Justification / 2. Causal Justification
Causes of beliefs are irrelevant to their contents [Wittgenstein]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Doubts can't exist if they are inexpressible or unanswerable [Wittgenstein]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
Total doubt can't even get started [Wittgenstein, by Williams,M]
One can mistrust one's own senses, but not one's own beliefs [Wittgenstein]
14. Science / B. Scientific Theories / 3. Instrumentalism
The 'Tractatus' is instrumentalist about laws of nature [Wittgenstein, by Armstrong]
14. Science / C. Induction / 2. Aims of Induction
Induction accepts the simplest law that fits our experiences [Wittgenstein]
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
Explanation and understanding are the same [Wittgenstein]
Explanation gives understanding by revealing the full multiplicity of the thing [Wittgenstein]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
The modern worldview is based on the illusion that laws explain nature [Wittgenstein]
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
A machine strikes us as being a rule of movement [Wittgenstein]
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
If an explanation is good, the symbol is used properly in the future [Wittgenstein]
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
I don't have the opinion that people have minds; I just treat them as such [Wittgenstein]
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / d. Other minds by analogy
It is irresponsible to generalise from my own case of pain to other people's [Wittgenstein]
To imagine another's pain by my own, I must imagine a pain I don't feel, by one I do feel [Wittgenstein]
15. Nature of Minds / B. Features of Minds / 3. Privacy
If a lion could talk, we could not understand him [Wittgenstein]
If a lion could talk, it would be nothing like other lions [Dennett on Wittgenstein]
15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind
We apprehend small, finite mathematical structures by abstraction from patterns [Shapiro]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
The philosophical I is the metaphysical subject, the limit - not a part of the world [Wittgenstein]
The subject stands outside our understanding of the world [Wittgenstein]
16. Persons / C. Self-Awareness / 1. Introspection
To say that I 'know' I am in pain means nothing more than that I AM in pain [Wittgenstein]
16. Persons / D. Continuity of the Self / 3. Reference of 'I'
'I' is a subject in 'I am in pain' and an object in 'I am bleeding' [Wittgenstein, by McGinn]
16. Persons / E. Rejecting the Self / 4. Denial of the Self
The modern idea of the subjective soul is composite, and impossible [Wittgenstein]
17. Mind and Body / D. Property Dualism / 6. Mysterianism
Why are we not aware of the huge gap between mind and brain in ordinary life? [Wittgenstein]
18. Thought / A. Modes of Thought / 1. Thought
Thought is an activity which we perform by the expression of it [Wittgenstein]
18. Thought / A. Modes of Thought / 6. Judgement / b. Error
The form of a proposition must show why nonsense is unjudgeable [Wittgenstein]
18. Thought / A. Modes of Thought / 10. Rule Following
An 'inner process' stands in need of outward criteria [Wittgenstein]
Every course of action can either accord or conflict with a rule, so there is no accord or conflict [Wittgenstein]
One cannot obey a rule 'privately', because that is a practice, not the same as thinking one is obeying [Wittgenstein]
If individuals can't tell if they are following a rule, how does a community do it? [Grayling on Wittgenstein]
18. Thought / C. Content / 6. Broad Content
Is white simple, or does it consist of the colours of the rainbow? [Wittgenstein]
Externalist accounts of mental content begin in Wittgenstein [Wittgenstein, by Heil]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
Possessing a concept is knowing how to go on [Wittgenstein, by Peacocke]
Concepts direct our interests and investigations, and express those interests [Wittgenstein]
Man learns the concept of the past by remembering [Wittgenstein]
18. Thought / D. Concepts / 4. Structure of Concepts / h. Family resemblance
Various games have a 'family resemblance', as their similarities overlap and criss-cross [Wittgenstein]
18. Thought / D. Concepts / 5. Concepts and Language / a. Concepts and language
What can be said is what can be thought, so language shows the limits of thought [Wittgenstein, by Grayling]
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
Abstract objects might come by abstraction over an equivalence class of base entities [Shapiro]
19. Language / A. Nature of Meaning / 1. Meaning
Wittgenstein rejected his earlier view that the form of language is the form of the world [Wittgenstein, by Morris,M]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
The 'form' of the picture is its possible combinations [Wittgenstein]
Propositions assemble a world experimentally, like the model of a road accident [Wittgenstein]
Language pictures the essence of the world [Wittgenstein]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
To understand a proposition means to know what is the case if it is true [Wittgenstein]
A proposition draws a line around the facts which agree with it [Wittgenstein]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
You can't believe it if you can't imagine a verification for it [Wittgenstein]
The meaning of a proposition is the mode of its verification [Wittgenstein]
Good philosophy asserts science, and demonstrates the meaninglessness of metaphysics [Wittgenstein]
Asking about verification is only one way of asking about the meaning of a proposition [Wittgenstein]
19. Language / A. Nature of Meaning / 6. Meaning as Use
For Wittgenstein, words are defined by their use, just as chess pieces are [Wittgenstein, by Fogelin]
We do not achieve meaning and understanding in our heads, but in the world [Wittgenstein, by Rowlands]
We all seem able to see quite clearly how sentences represent things when we use them [Wittgenstein]
In the majority of cases the meaning of a word is its use in the language [Wittgenstein]
19. Language / A. Nature of Meaning / 7. Meaning Holism / a. Sentence meaning
Words function only in propositions, like levers in a machine [Wittgenstein]
19. Language / A. Nature of Meaning / 7. Meaning Holism / b. Language holism
To understand a sentence means to understand a language [Wittgenstein]
19. Language / A. Nature of Meaning / 10. Denial of Meanings
If you are not certain of any fact, you cannot be certain of the meaning of your words either [Wittgenstein]
We don't have 'meanings' in our minds in addition to verbal expressions [Wittgenstein]
Make the following experiment: say "It's cold here" and mean "It's warm here" [Wittgenstein]
19. Language / B. Reference / 1. Reference theories
How do words refer to sensations? [Wittgenstein]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
The standard metre in Paris is neither one metre long nor not one metre long [Wittgenstein]
19. Language / C. Assigning Meanings / 4. Compositionality
Propositions use old expressions for a new sense [Wittgenstein]
Propositions are understood via their constituents [Wittgenstein]
19. Language / D. Propositions / 1. Propositions
A proposition is any expression which can be significantly negated [Wittgenstein]
19. Language / D. Propositions / 2. Abstract Propositions / b. Propositions as possible worlds
Pictures are possible situations in logical space [Wittgenstein]
19. Language / D. Propositions / 4. Mental Propositions
A thought is mental constituents that relate to reality as words do [Wittgenstein]
19. Language / F. Communication / 4. Private Language
Solipsism is correct, but can only be shown, not said, by the limits of my personal language [Wittgenstein]
Was Wittgenstein's problem between individual and community, or between occasions for an individual? [Rowlands on Wittgenstein]
If a brilliant child invented a name for a private sensation, it couldn't communicate it [Wittgenstein]
We cannot doublecheck mental images for correctness (or confirm news with many copies of the paper) [Wittgenstein]
If we only named pain by our own case, it would be like naming beetles by looking in a private box [Wittgenstein]
If the reference is private, that is incompatible with the sense being public [Wittgenstein, by Scruton]
Getting from perceptions to words cannot be a private matter; the rules need an institution of use [Wittgenstein]
To imagine a language means to imagine a form of life [Wittgenstein]
19. Language / F. Communication / 6. Interpreting Language / a. Translation
We translate by means of proposition constituents, not by whole propositions [Wittgenstein]
19. Language / F. Communication / 6. Interpreting Language / b. Indeterminate translation
The doctrine of indeterminacy of translation seems implied by the later Wittgenstein [Wittgenstein, by Quine]
19. Language / F. Communication / 6. Interpreting Language / c. Principle of charity
Common human behaviour enables us to interpret an unknown language [Wittgenstein]
To communicate, language needs agreement in judgment as well as definition [Wittgenstein]
20. Action / A. Definition of Action / 3. Actions and Events
What is left over if I subtract my arm going up from my raising my arm? [Wittgenstein]
21. Aesthetics / A. Aesthetic Experience / 2. Aesthetic Attitude
Consider: "Imagine this butterfly exactly as it is, but ugly instead of beautiful" [Wittgenstein]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / b. Defining ethics
Ethics cannot be put into words [Wittgenstein]
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
The sense of the world must lie outside the world [Wittgenstein]
25. Social Practice / F. Life Issues / 4. Suicide
Absolute prohibitions are the essence of ethics, and suicide is the most obvious example [Wittgenstein]
25. Social Practice / F. Life Issues / 6. Animal Rights
Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley]
26. Natural Theory / D. Laws of Nature / 11. Against Laws of Nature
Laws of nature are an aspect of the phenomena, and are just our mode of description [Wittgenstein]
29. Religion / D. Religious Issues / 1. Religious Commitment / b. Religious Meaning
Grammar tells what kind of object anything is - and theology is a kind of grammar [Wittgenstein]
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
The human body is the best picture of the human soul [Wittgenstein]