Combining Philosophers

All the ideas for Anaxarchus, Jonathan Wolff and George Boolos

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64 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory
The logic of ZF is classical first-order predicate logic with identity [Boolos]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
A few axioms of set theory 'force themselves on us', but most of them don't [Boolos]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / h. Axiom of Replacement VII
Do the Replacement Axioms exceed the iterative conception of sets? [Boolos, by Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
The use of plurals doesn't commit us to sets; there do not exist individuals and collections [Boolos]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / d. Naïve logical sets
Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size is weak (Fs only collect is something the same size does) or strong (fewer Fs than objects) [Boolos, by Potter]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Does a bowl of Cheerios contain all its sets and subsets? [Boolos]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
Monadic second-order logic might be understood in terms of plural quantifiers [Boolos, by Shapiro]
Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
Boolos showed how plural quantifiers can interpret monadic second-order logic [Boolos, by Linnebo]
Any sentence of monadic second-order logic can be translated into plural first-order logic [Boolos, by Linnebo]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
Identity is clearly a logical concept, and greatly enhances predicate calculus [Boolos]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
'∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order quantifiers are just like plural quantifiers in ordinary language, with no extra ontology [Boolos, by Shapiro]
5. Theory of Logic / G. Quantification / 6. Plural Quantification
We should understand second-order existential quantifiers as plural quantifiers [Boolos, by Shapiro]
Plural forms have no more ontological commitment than to first-order objects [Boolos]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
Boolos invented plural quantification [Boolos, by Benardete,JA]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Infinite natural numbers is as obvious as infinite sentences in English [Boolos]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / f. Uncountable infinities
Mathematics and science do not require very high orders of infinity [Boolos]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Many concepts can only be expressed by second-order logic [Boolos]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
Mathematics isn't surprising, given that we experience many objects as abstract [Boolos]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / b. Commitment of quantifiers
First- and second-order quantifiers are two ways of referring to the same things [Boolos]
8. Modes of Existence / D. Universals / 1. Universals
It is lunacy to think we only see ink-marks, and not word-types [Boolos]
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
I am a fan of abstract objects, and confident of their existence [Boolos]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
An 'abstraction principle' says two things are identical if they are 'equivalent' in some respect [Boolos]
24. Political Theory / A. Basis of a State / 1. A People / b. The natural life
Human beings can never really flourish in a long-term state of nature [Wolff,J]
24. Political Theory / A. Basis of a State / 1. A People / c. A unified people
Collective rationality is individuals doing their best, assuming others all do the same [Wolff,J]
Should love be the first virtue of a society, as it is of the family? [Wolff,J]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / c. Social contract
For utilitarians, consent to the state is irrelevant, if it produces more happiness [Wolff,J]
Social contract theory has the attracton of including everyone, and being voluntary [Wolff,J]
Maybe voting in elections is a grant of legitimacy to the winners [Wolff,J]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / d. General will
We can see the 'general will' as what is in the general interest [Wolff,J]
24. Political Theory / C. Ruling a State / 2. Leaders / c. Despotism
How can dictators advance the interests of the people, if they don't consult them about interests? [Wolff,J]
24. Political Theory / C. Ruling a State / 3. Government / a. Government
'Separation of powers' allows legislative, executive and judicial functions to monitor one another [Wolff,J]
24. Political Theory / D. Ideologies / 1. Ideology
Political choice can be by utility, or maximin, or maximax [Wolff,J]
24. Political Theory / D. Ideologies / 2. Anarchism
A realistic and less utopian anarchism looks increasingly like liberal democracy [Wolff,J]
It is hard for anarchists to deny that we need experts [Wolff,J]
24. Political Theory / D. Ideologies / 4. Social Utilitarianism
Utilitarianism probably implies a free market plus welfare [Wolff,J]
24. Political Theory / D. Ideologies / 5. Democracy / a. Nature of democracy
A system of democracy which includes both freedom and equality is almost impossible [Wolff,J]
Democracy expresses equal respect (which explains why criminals forfeit the vote) [Wolff,J]
Democracy has been seen as consistent with many types of inequality [Wolff,J]
A true democracy could not tolerate slavery, exploitation or colonialism [Wolff,J]
24. Political Theory / D. Ideologies / 5. Democracy / b. Consultation
We should decide whether voting is for self-interests, or for the common good [Wolff,J]
Condorcet proved that sensible voting leads to an emphatically right answer [Wolff,J]
24. Political Theory / D. Ideologies / 5. Democracy / e. Democratic minorities
Occasional defeat is acceptable, but a minority that is continually defeated is a problem [Wolff,J]
25. Social Practice / A. Freedoms / 4. Free market
Market prices indicate shortages and gluts, and where the profits are to be made [Wolff,J]
25. Social Practice / A. Freedoms / 5. Freedom of lifestyle
Liberty principles can't justify laws against duelling, incest between siblings and euthanasia [Wolff,J]
Either Difference allows unequal liberty, or Liberty makes implementing Difference impossible [Wolff,J]
25. Social Practice / B. Equalities / 1. Grounds of equality
Utilitarians argue for equal distribution because of diminishing utility of repetition [Wolff,J]
Difference Principle: all inequalities should be in favour of the disadvantaged [Wolff,J]
25. Social Practice / B. Equalities / 2. Political equality
Political equality is not much use without social equality [Wolff,J]
25. Social Practice / C. Rights / 1. Basis of Rights
Standard rights: life, free speech, assembly, movement, vote, stand (plus shelter, food, health?) [Wolff,J]
If natural rights are axiomatic, there is then no way we can defend them [Wolff,J]
If rights are natural, rather than inferred, how do we know which rights we have? [Wolff,J]
25. Social Practice / C. Rights / 4. Property rights
Utilitarians might say property ownership encourages the best use of the land [Wolff,J]
25. Social Practice / D. Justice / 1. Basis of justice
Rights and justice are only the last resorts of a society, something to fall back on [Wolff,J]
25. Social Practice / D. Justice / 2. The Law / d. Legal positivism
Following some laws is not a moral matter; trivial traffic rules, for example [Wolff,J]