Combining Philosophers

All the ideas for Anaxarchus, Paul Johnson and George Boolos

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48 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 / D. Ideologies / 10. Theocracy
In Mosaic legal theory, crimes are sins and sins are crimes [Johnson,P]
Because human life is what is sacred, Mosaic law has no death penalty for property violations [Johnson,P]
25. Social Practice / A. Freedoms / 1. Slavery
The Pharisees undermined slavery, by giving slaves responsibility and status in law courts [Johnson,P]
25. Social Practice / B. Equalities / 3. Legal equality
Mosaic law was the first to embody the rule of law, and equality before the law [Johnson,P]
25. Social Practice / F. Life Issues / 1. Causing Death
Man's life is sacred, because it is made in God's image [Johnson,P]
29. Religion / A. Polytheistic Religion / 2. Greek Polytheism
The Jews sharply distinguish human and divine, but the Greeks pull them closer together [Johnson,P]
29. Religion / B. Monotheistic Religion / 2. Judaism
A key moment is the idea of a single moral God, who imposes his morality on humanity [Johnson,P]
Sampson illustrates the idea that religious heroes often begin as outlaws and semi-criminals [Johnson,P]
Isaiah moved Israelite religion away from the local, onto a more universal plane [Johnson,P]
The Torah pre-existed creation, and was its blueprint [Johnson,P]
Judaism involves circumcision, Sabbath, Passover, Pentecost, Tabernacles, New Year, and Atonement [Johnson,P]
In exile the Jews became a nomocracy [Johnson,P]
29. Religion / B. Monotheistic Religion / 3. Zoroastrianism
Zoroastrians believed in one eternal beneficent being, Creator through the holy spirit [Johnson,P]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Immortality based on judgement of merit was developed by the Egyptians (not the Jews) [Johnson,P]
The main doctrine of the Pharisees was belief in resurrection and the afterlife [Johnson,P]
29. Religion / D. Religious Issues / 2. Immortality / d. Heaven
Pious Jews saw heaven as a vast library [Johnson,P]