Combining Texts

All the ideas for 'What Price Bivalence?', 'Mathematical logic and theory of types' and 'The Language of Morals'

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13 ideas

4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
Classes can be reduced to propositional functions [Russell, by Hanna]
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
Bivalence applies not just to sentences, but that general terms are true or false of each object [Quine]
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / d. Russell's paradox
The class of classes which lack self-membership leads to a contradiction [Russell, by Grayling]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Type theory seems an extreme reaction, since self-exemplification is often innocuous [Swoyer on Russell]
Russell's improvements blocked mathematics as well as paradoxes, and needed further axioms [Russell, by Musgrave]
Type theory means that features shared by different levels cannot be expressed [Morris,M on Russell]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
Ramified types can be defended as a system of intensional logic, with a 'no class' view of sets [Russell, by Linsky,B]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
A set does not exist unless at least one of its specifications is predicative [Russell, by Bostock]
Russell is a conceptualist here, saying some abstracta only exist because definitions create them [Russell, by Bostock]
Vicious Circle says if it is expressed using the whole collection, it can't be in the collection [Russell, by Bostock]
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
The goodness of a picture supervenes on the picture; duplicates must be equally good [Hare]
7. Existence / D. Theories of Reality / 10. Vagueness / d. Vagueness as linguistic
Terms learned by ostension tend to be vague, because that must be quick and unrefined [Quine]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / i. Prescriptivism
In primary evaluative words like 'ought' prescription is constant but description can vary [Hare, by Hooker,B]