### Ideas from 'Modality' by Joseph Melia [2003], by Theme Structure

#### [found in 'Modality' by Melia,Joseph [Acumen 2003,1-902683-48-x]].

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###### 2. Reason / A. Nature of Reason / 1. On Reason
 5750 Consistency is modal, saying propositions are consistent if they could be true together
###### 4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
 5737 Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets
###### 4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
 5744 First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious)
###### 5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
 5740 Second-order logic needs second-order variables and quantification into predicate position
###### 5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
 5741 If every model that makes premises true also makes conclusion true, the argument is valid
###### 7. Existence / D. Theories of Reality / 8. Facts / a. Facts
 5735 Maybe names and predicates can capture any fact
 5736 No sort of plain language or levels of logic can express modal facts properly
###### 9. Objects / F. Identity among Objects / 7. Indiscernible Objects
 5746 The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities
###### 10. Modality / A. Necessity / 2. Nature of Necessity
 5738 We may be sure that P is necessary, but is it necessarily necessary?
###### 10. Modality / A. Necessity / 4. De re / De dicto modality
 5732 'De re' modality is about things themselves, 'de dicto' modality is about propositions
###### 10. Modality / B. Possibility / 1. Possibility
 5739 Sometimes we want to specify in what ways a thing is possible
###### 10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
 5734 Possible worlds make it possible to define necessity and counterfactuals without new primitives
 5742 In possible worlds semantics the modal operators are treated as quantifiers
 5743 If possible worlds semantics is not realist about possible worlds, logic becomes merely formal
 5749 Possible worlds could be real as mathematics, propositions, properties, or like books
###### 10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
 5751 The truth of propositions at possible worlds are implied by the world, just as in books
###### 19. Language / A. Nature of Meaning / 5. Meaning as Verification
 5748 We accept unverifiable propositions because of simplicity, utility, explanation and plausibility