Combining Texts

All the ideas for 'Cours d'Analyse', 'Grundgesetze der Arithmetik 1 (Basic Laws)' and 'Nihilism without Self-Contradiction'

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14 ideas

2. Reason / F. Fallacies / 7. Ad Hominem
We should always apply someone's theory of meaning to their own utterances [Liggins]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn]
5. Theory of Logic / G. Quantification / 4. Substitutional Quantification
Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege]
5. Theory of Logic / G. Quantification / 6. Plural Quantification
We normally formalise 'There are Fs' with singular quantification and predication, but this may be wrong [Liggins]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers are ratios of quantities, such as lengths or masses [Frege]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / k. Infinitesimals
Values that approach zero, becoming less than any quantity, are 'infinitesimals' [Cauchy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
When successive variable values approach a fixed value, that is its 'limit' [Cauchy]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright]
Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / a. Early logicism
My Basic Law V is a law of pure logic [Frege]
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
Nihilists needn't deny parts - they can just say that some of the xs are among the ys [Liggins]
18. Thought / D. Concepts / 3. Ontology of Concepts / c. Fregean concepts
A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett]
Frege took the study of concepts to be part of logic [Frege, by Shapiro]