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All the ideas for 'Exigency to Exist in Essences', 'Goodbye Descartes' and 'Structures and Structuralism in Phil of Maths'

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34 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
Logic was merely a branch of rhetoric until the scientific 17th century [Devlin]
3. Truth / F. Semantic Truth / 2. Semantic Truth
While true-in-a-model seems relative, true-in-all-models seems not to be [Reck/Price]
4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'No councillors are bankers' and 'All bankers are athletes' implies 'Some athletes are not councillors' [Devlin]
4. Formal Logic / B. Propositional Logic PL / 1. Propositional Logic
Modern propositional inference replaces Aristotle's 19 syllogisms with modus ponens [Devlin]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
Predicate logic retains the axioms of propositional logic [Devlin]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
ZFC set theory has only 'pure' sets, without 'urelements' [Reck/Price]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Situation theory is logic that takes account of context [Devlin]
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
Golden ages: 1900-1960 for pure logic, and 1950-1985 for applied logic [Devlin]
Montague's intensional logic incorporated the notion of meaning [Devlin]
5. Theory of Logic / B. Logical Consequence / 7. Strict Implication
Where a conditional is purely formal, an implication implies a link between premise and conclusion [Devlin]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Sentences of apparent identical form can have different contextual meanings [Devlin]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Three types of variable in second-order logic, for objects, functions, and predicates/sets [Reck/Price]
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox
Space and time are atomic in the arrow, and divisible in the tortoise [Devlin]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
'Analysis' is the theory of the real numbers [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / a. Axioms for numbers
Mereological arithmetic needs infinite objects, and function definitions [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
Peano Arithmetic can have three second-order axioms, plus '1' and 'successor' [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set-theory gives a unified and an explicit basis for mathematics [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Structuralism emerged from abstract algebra, axioms, and set theory and its structures [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / b. Varieties of structuralism
Relativist Structuralism just stipulates one successful model as its arithmetic [Reck/Price]
There are 'particular' structures, and 'universal' structures (what the former have in common) [Reck/Price]
Pattern Structuralism studies what isomorphic arithmetic models have in common [Reck/Price]
There are Formalist, Relativist, Universalist and Pattern structuralism [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
Formalist Structuralism says the ontology is vacuous, or formal, or inference relations [Reck/Price]
Maybe we should talk of an infinity of 'possible' objects, to avoid arithmetic being vacuous [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / d. Platonist structuralism
Universalist Structuralism is based on generalised if-then claims, not one particular model [Reck/Price]
Universalist Structuralism eliminates the base element, as a variable, which is then quantified out [Reck/Price]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
The existence of an infinite set is assumed by Relativist Structuralism [Reck/Price]
7. Existence / A. Nature of Existence / 5. Reason for Existence
Possibles demand existence, so as many of them as possible must actually exist [Leibniz]
God's sufficient reason for choosing reality is in the fitness or perfection of possibilities [Leibniz]
8. Modes of Existence / E. Nominalism / 6. Mereological Nominalism
A nominalist might avoid abstract objects by just appealing to mereological sums [Reck/Price]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
The actual universe is the richest composite of what is possible [Leibniz]
13. Knowledge Criteria / E. Relativism / 5. Language Relativism
People still say the Hopi have no time concepts, despite Whorf's later denial [Devlin]
19. Language / C. Assigning Meanings / 1. Syntax
How do we parse 'time flies like an arrow' and 'fruit flies like an apple'? [Devlin]
19. Language / D. Propositions / 2. Abstract Propositions / a. Propositions as sense
The distinction between sentences and abstract propositions is crucial in logic [Devlin]