Combining Texts

All the ideas for 'Classical Cosmology (frags)', 'In Defense of Essentialism' and 'On Second-Order Logic'

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17 ideas

5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
14249 Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley]
10830 Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
10829 A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
10832 '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos]
5. Theory of Logic / K. Features of Logics / 4. Completeness
10834 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
13841 Why should compactness be definitive of logic? [Boolos, by Hacking]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
10833 Many concepts can only be expressed by second-order logic [Boolos]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
14193 'Substance theorists' take modal properties as primitive, without structure, just falling under a sortal [Paul,LA]
14195 If an object's sort determines its properties, we need to ask what determines its sort [Paul,LA]
14196 Substance essentialism says an object is multiple, as falling under various different sortals [Paul,LA]
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
14198 Absolutely unrestricted qualitative composition would allow things with incompatible properties [Paul,LA]
9. Objects / D. Essence of Objects / 2. Types of Essence
14190 Deep essentialist objects have intrinsic properties that fix their nature; the shallow version makes it contextual [Paul,LA]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
14191 Deep essentialists say essences constrain how things could change; modal profiles fix natures [Paul,LA]
9. Objects / D. Essence of Objects / 15. Against Essentialism
14192 Essentialism must deal with charges of arbitrariness, and failure to reduce de re modality [Paul,LA]
14197 An object's modal properties don't determine its possibilities [Paul,LA]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
14189 'Modal realists' believe in many concrete worlds, 'actualists' in just this world, 'ersatzists' in abstract other worlds [Paul,LA]
27. Natural Reality / E. Cosmology / 1. Cosmology
5994 Is the cosmos open or closed, mechanical or teleological, alive or inanimate, and created or eternal? [Robinson,TM, by PG]