Combining Texts

All the ideas for 'Aristotle and Descartes on Matter', 'Higher-Order Logic' and 'The Good State'

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22 ideas

4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
10301 The axiom of choice is controversial, but it could be replaced [Shapiro]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
10588 First-order logic is Complete, and Compact, with the Löwenheim-Skolem Theorems [Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
10298 Some say that second-order logic is mathematics, not logic [Shapiro]
10299 If the aim of logic is to codify inferences, second-order logic is useless [Shapiro]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
10300 Logical consequence can be defined in terms of the logical terminology [Shapiro]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
10290 Second-order variables also range over properties, sets, relations or functions [Shapiro]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
10590 Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
10296 The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [Shapiro]
10297 The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
10292 Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / e. Peano arithmetic 2nd-order
10294 Second-order logic has the expressive power for mathematics, but an unworkable model theory [Shapiro]
8. Modes of Existence / B. Properties / 11. Properties as Sets
10591 Logicians use 'property' and 'set' interchangeably, with little hanging on it [Shapiro]
24. Political Theory / A. Basis of a State / 3. Natural Values / c. Natural rights
23262 Experience, sympathy and history are sensible grounds for laying claim to rights [Grayling]
24. Political Theory / C. Ruling a State / 1. Social Power
23263 Politics is driven by power cliques [Grayling]
24. Political Theory / D. Ideologies / 5. Democracy / a. Nature of democracy
23255 It is essential for democracy that voting is free and well informed [Grayling]
23254 Democracies should require a supermajority for major questions [Grayling]
24. Political Theory / D. Ideologies / 5. Democracy / d. Representative democracy
23260 A cap on time of service would restrict party control and career ambitions [Grayling]
24. Political Theory / D. Ideologies / 5. Democracy / e. Democratic minorities
23253 Majority decisions are only acceptable if the minority interests are not vital [Grayling]
25. Social Practice / B. Equalities / 1. Grounds of equality
23256 Liberty and equality cannot be reconciled [Grayling]
25. Social Practice / D. Justice / 1. Basis of justice
23258 The very concept of democracy entails a need for justice [Grayling]
25. Social Practice / D. Justice / 2. The Law / a. Legal system
23259 There should be separate legislative, executive and judicial institutions [Grayling]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
19399 Prime matter is nothing when it is at rest [Leibniz]