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Single Idea 5738
[filed under theme 10. Modality / A. Necessity / 2. Nature of Necessity
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Full Idea
We may have fairly firm beliefs as to whether or not P is necessary, but many of us find ourselves at a complete loss when wondering whether or not P is necessarily necessary.
Gist of Idea
We may be sure that P is necessary, but is it necessarily necessary?
Source
Joseph Melia (Modality [2003], Ch.2)
Book Ref
Melia,Joseph: 'Modality' [Acumen 2003], p.28
A Reaction
I think it is questions like this which are pushing philosophy back towards some sort of rationalism. See Idea 3651, for example. A regress of necessities would be mad, so necessity must be taken as self-evident (in itself, though maybe not to us).
Related Idea
Idea 3651
Perceiving necessary connections is the essence of reasoning [Bonjour]
The
17 ideas
from Joseph 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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5734
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Possible worlds make it possible to define necessity and counterfactuals without new primitives
[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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5738
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We may be sure that P is necessary, but is it necessarily necessary?
[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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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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5739
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Sometimes we want to specify in what ways a thing is possible
[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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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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5750
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Consistency is modal, saying propositions are consistent if they could be true together
[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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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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