Combining Texts

All the ideas for 'Transworld Identity or worldbound Individuals?', 'A Rsum of Metaphysics' and 'Higher-Order Logic'

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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]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
11984 Asserting a possible property is to say it would have had the property if that world had been actual [Plantinga]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
11980 A possible world is a maximal possible state of affairs [Plantinga]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
11982 If possible Socrates differs from actual Socrates, the Indiscernibility of Identicals says they are different [Plantinga]
11983 It doesn't matter that we can't identify the possible Socrates; we can't identify adults from baby photos [Plantinga]
11985 If individuals can only exist in one world, then they can never lack any of their properties [Plantinga]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
11986 The counterparts of Socrates have self-identity, but only the actual Socrates has identity-with-Socrates [Plantinga]
11987 Counterpart Theory absurdly says I would be someone else if things went differently [Plantinga]
22. Metaethics / C. The Good / 3. Pleasure / a. Nature of pleasure
5049 Intelligent pleasure is the perception of beauty, order and perfection [Leibniz]
28. God / A. Divine Nature / 3. Divine Perfections
5048 Perfection is simply quantity of reality [Leibniz]
29. Religion / D. Religious Issues / 3. Problem of Evil / b. Human Evil
5050 Evil serves a greater good, and pain is necessary for higher pleasure [Leibniz]