Combining Texts

All the ideas for 'The Sign of Four', 'Higher-Order Logic' and 'The Morality of Happiness'

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21 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
10297 The Löwenheim-Skolem theorem seems to be a defect of first-order logic [Shapiro]
10590 Up Löwenheim-Skolem: if natural numbers satisfy wffs, then an infinite domain satisfies them [Shapiro]
10292 Downward Löwenheim-Skolem: if there's an infinite model, there is a countable model [Shapiro]
10296 The Löwenheim-Skolem Theorems fail for second-order languages with standard semantics [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]
14. Science / C. Induction / 1. Induction
22200 If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
3546 'Phronesis' should translate as 'practical intelligence', not as prudence [Annas]
22. Metaethics / C. The Good / 3. Pleasure / d. Sources of pleasure
3547 Epicureans achieve pleasure through character development [Annas]
23. Ethics / A. Egoism / 3. Cyrenaic School
3543 Cyrenaics pursue pleasure, but don't equate it with happiness [Annas]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
3541 Ancient ethics uses attractive notions, not imperatives [Annas]
23. Ethics / D. Deontological Ethics / 1. Deontology
3550 Principles cover life as a whole, where rules just cover actions [Annas]
23. Ethics / D. Deontological Ethics / 2. Duty
3551 Virtue theory tries to explain our duties in terms of our character [Annas]
23. Ethics / D. Deontological Ethics / 6. Motivation for Duty
3552 If excessively good actions are admirable but not required, then duty isn't basic [Annas]
23. Ethics / E. Utilitarianism / 1. Utilitarianism
3542 We should do good when necessary, not maximise it [Annas]