Combining Texts

All the ideas for 'Identity and Spatio-Temporal Continuity', 'Actualism and Possible Worlds' and 'Modality'

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25 ideas

2. Reason / A. Nature of Reason / 1. On Reason
Consistency is modal, saying propositions are consistent if they could be true together [Melia]
4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia]
5. Theory of Logic / G. Quantification / 5. Second-Order Quantification
Second-order logic needs second-order variables and quantification into predicate position [Melia]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
If every model that makes premises true also makes conclusion true, the argument is valid [Melia]
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
Necessary beings (numbers, properties, sets, propositions, states of affairs, God) exist in all possible worlds [Plantinga]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
No sort of plain language or levels of logic can express modal facts properly [Melia]
Maybe names and predicates can capture any fact [Melia]
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
'Ultimate sortals' cannot explain ontological categories [Westerhoff on Wiggins]
9. Objects / D. Essence of Objects / 1. Essences of Objects
Socrates is a contingent being, but his essence is not; without Socrates, his essence is unexemplified [Plantinga]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia]
10. Modality / A. Necessity / 2. Nature of Necessity
We may be sure that P is necessary, but is it necessarily necessary? [Melia]
10. Modality / A. Necessity / 4. De re / De dicto modality
'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia]
10. Modality / B. Possibility / 1. Possibility
Sometimes we want to specify in what ways a thing is possible [Melia]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Possible worlds clarify possibility, propositions, properties, sets, counterfacts, time, determinism etc. [Plantinga]
Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia]
In possible worlds semantics the modal operators are treated as quantifiers [Melia]
If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia]
Possible worlds could be real as mathematics, propositions, properties, or like books [Melia]
10. Modality / E. Possible worlds / 1. Possible Worlds / d. Possible worlds actualism
Plantinga's actualism is nominal, because he fills actuality with possibilia [Stalnaker on Plantinga]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / b. Worlds as fictions
The truth of propositions at possible worlds are implied by the world, just as in books [Melia]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
Plantinga has domains of sets of essences, variables denoting essences, and predicates as functions [Plantinga, by Stalnaker]
Plantinga's essences have their own properties - so will have essences, giving a hierarchy [Stalnaker on Plantinga]
19. Language / D. Propositions / 1. Propositions
Are propositions and states of affairs two separate things, or only one? I incline to say one [Plantinga]