Combining Philosophers

All the ideas for Herodotus, George Boolos and Yuval Noah Harari

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61 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
The Scientific Revolution was the discovery of our own ignorance [Harari]
For millenia people didn't know how to convert one type of energy into another [Harari]
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]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
An 'abstraction principle' says two things are identical if they are 'equivalent' in some respect [Boolos]
23. Ethics / C. Virtue Theory / 4. External Goods / c. Wealth
Money does produce happiness, but only up to a point [Harari]
24. Political Theory / A. Basis of a State / 1. A People / c. A unified people
If a group is bound by gossip, the natural size is 150 people [Harari]
24. Political Theory / A. Basis of a State / 2. Population / a. Human population
Since 1500 human population has increased fourteenfold, and consumption far more [Harari]
People 300m tons; domesticated animals 700m tons; larger wild animals 100m tons [Harari]
24. Political Theory / B. Nature of a State / 1. Purpose of a State
The Nazi aim was to encourage progressive evolution, and avoid degeneration [Harari]
24. Political Theory / B. Nature of a State / 5. Culture
We stabilise societies with dogmas, either of dubious science, or of non-scientific values [Harari]
24. Political Theory / D. Ideologies / 6. Liberalism / b. Liberal individualism
The state fostered individualism, to break the power of family and community [Harari]
24. Political Theory / D. Ideologies / 7. Communitarianism / a. Communitarianism
In 1750 losing your family and community meant death [Harari]
24. Political Theory / D. Ideologies / 11. Capitalism
The sacred command of capitalism is that profits must be used to increase production [Harari]
The main rule of capitalism is that all other goods depend on economic growth [Harari]
The progress of capitalism depends entirely on the new discoveries and gadgets of science [Harari]
In capitalism the rich invest, and the rest of us go shopping [Harari]
25. Social Practice / A. Freedoms / 4. Free market
No market is free of political bias, and markets need protection of their freedoms [Harari]
25. Social Practice / A. Freedoms / 5. Freedom of lifestyle
Freedom may work against us, as individuals can choose to leave, and make fewer commitments [Harari]
25. Social Practice / E. Policies / 1. War / e. Peace
Real peace is the implausibility of war (and not just its absence) [Harari]
25. Social Practice / E. Policies / 4. Taxation
Financing is increasingly through credit rather than taxes; people prefer investing to taxation [Harari]
25. Social Practice / E. Policies / 5. Education / d. Study of history
The more you know about history, the harder it becomes to explain [Harari]
History teaches us that the present was not inevitable, and shows us the possibilities [Harari]
28. God / C. Attitudes to God / 1. Monotheism
In order to explain both order and evil, a single evil creator is best, but no one favours that [Harari]
29. Religion / A. Polytheistic Religion / 1. Animism
Animism is belief that every part of nature is aware and feeling, and can communicate [Harari]
29. Religion / A. Polytheistic Religion / 2. Greek Polytheism
Most polytheist recognise one supreme power or law, behind the various gods [Harari]
Polytheism is open-minded, and rarely persecutes opponents [Harari]
Mythologies are usual contracts with the gods, exchanging devotion for control of nature [Harari]
29. Religion / A. Polytheistic Religion / 4. Dualist Religion
Dualist religions see everything as a battleground of good and evil forces [Harari]
Dualist religions say the cosmos is a battleground, so can’t explain its order [Harari]
Manichaeans and Gnostics: good made spirit, evil made flesh [Harari]
29. Religion / B. Monotheistic Religion / 1. Monotheistic Religion
Monotheism appeared in Egypt in 1350 BCE, when the god Aten was declared supreme [Harari]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus]