Combining Texts

All the ideas for 'Universal Prescriptivism', 'Principles of Arithmetic, by a new method' and 'Must We Believe in Set Theory?'

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25 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 / 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]
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 / d. Peano arithmetic
All models of Peano axioms are isomorphic, so the models all seem equally good for natural numbers [Cartwright,R on Peano]
PA concerns any entities which satisfy the axioms [Peano, by Bostock]
Peano axioms not only support arithmetic, but are also fairly obvious [Peano, by Russell]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
We can add Reflexion Principles to Peano Arithmetic, which assert its consistency or soundness [Halbach on Peano]
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]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
Arithmetic can have even simpler logical premises than the Peano Axioms [Russell on Peano]
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]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
How can intuitionists distinguish universal convictions from local cultural ones? [Hare]
You can't use intuitions to decide which intuitions you should cultivate [Hare]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
Emotivists mistakenly think all disagreements are about facts, and so there are no moral reasons [Hare]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
Prescriptivism sees 'ought' statements as imperatives which are universalisable [Hare]
If morality is just a natural or intuitive description, that leads to relativism [Hare]
Descriptivism say ethical meaning is just truth-conditions; prescriptivism adds an evaluation [Hare]
If there can be contradictory prescriptions, then reasoning must be involved [Hare]
An 'ought' statement implies universal application [Hare]
Prescriptivism implies a commitment, but descriptivism doesn't [Hare]
23. Ethics / D. Deontological Ethics / 3. Universalisability
Moral judgements must invoke some sort of principle [Hare]