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Single Idea 5737
[filed under theme 4. Formal Logic / C. Predicate Calculus PC / 1. Predicate Calculus PC
]
Full Idea
First-order predicate language has four connectives, two quantifiers, variables, predicates, equality, names, and brackets.
Gist of Idea
Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets
Source
Joseph Melia (Modality [2003], Ch.2)
Book Ref
Melia,Joseph: 'Modality' [Acumen 2003], p.22
A Reaction
Look up the reference for the details! The spirit of logic is seen in this basic framework, and the main interest is in the ontological commitment of the items on the list. The list is either known a priori, or it is merely conventional.
The
17 ideas
from Joseph Melia
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5734
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Possible worlds make it possible to define necessity and counterfactuals without new primitives
[Melia]
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5732
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'De re' modality is about things themselves, 'de dicto' modality is about propositions
[Melia]
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5739
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Sometimes we want to specify in what ways a thing is possible
[Melia]
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5742
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In possible worlds semantics the modal operators are treated as quantifiers
[Melia]
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5743
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If possible worlds semantics is not realist about possible worlds, logic becomes merely formal
[Melia]
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5740
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Second-order logic needs second-order variables and quantification into predicate position
[Melia]
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5741
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If every model that makes premises true also makes conclusion true, the argument is valid
[Melia]
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5735
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Maybe names and predicates can capture any fact
[Melia]
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5736
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No sort of plain language or levels of logic can express modal facts properly
[Melia]
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5737
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Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets
[Melia]
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5738
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We may be sure that P is necessary, but is it necessarily necessary?
[Melia]
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5744
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First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious)
[Melia]
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5746
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The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities
[Melia]
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5748
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We accept unverifiable propositions because of simplicity, utility, explanation and plausibility
[Melia]
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5749
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Possible worlds could be real as mathematics, propositions, properties, or like books
[Melia]
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5750
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Consistency is modal, saying propositions are consistent if they could be true together
[Melia]
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5751
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The truth of propositions at possible worlds are implied by the world, just as in books
[Melia]
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