more from this thinker
|
more from this text
Single Idea 8260
[filed under theme 10. Modality / A. Necessity / 6. Logical Necessity
]
Full Idea
'Strict' logical necessity is true by the laws of logic alone; 'narrow' logical necessity is true by the laws of logic plus definitions of non-logical terms; 'broad' logical necessity is true in every possible world where the laws of logic hold.
Gist of Idea
Logical necessity can be 'strict' (laws), or 'narrow' (laws and definitions), or 'broad' (all logical worlds)
Source
E.J. Lowe (The Possibility of Metaphysics [1998], 1.4)
Book Ref
Lowe,E.J.: 'The Possibility of Metaphysics' [OUP 2001], p.14
A Reaction
Lowe then says the third is close to 'metaphysical' necessity. I am unable to distinguish the third from the first. You can't claim that a logical implication holds in this world, but not in another possible world which has the same rules of implication.
The
40 ideas
with the same theme
[necessity because of logic or definitions]:
17852
|
A thing has a feature necessarily if its denial brings a contradiction
[Aristotle]
|
12259
|
Reasoning is when some results follow necessarily from certain claims
[Aristotle]
|
16490
|
Some facts about experience feel like logical necessities
[Russell]
|
9001
|
Frege moved Kant's question about a priori synthetic to 'how is logical certainty possible?'
[Quine]
|
12188
|
Contrary to some claims, Quine does not deny logical necessity
[Quine, by McFetridge]
|
15230
|
Logical necessity is grounded in the logical form of a statement
[Harré/Madden]
|
13820
|
The idea that anything which can be proved is necessary has a problem with empty names
[Bostock]
|
15083
|
The fundamental case of logical necessity is the valid conclusion of an inference
[McFetridge, by Hale]
|
15084
|
In the McFetridge view, logical necessity means a consequent must be true if the antecedent is
[McFetridge, by Hale]
|
12181
|
Traditionally, logical necessity is the strongest, and entails any other necessities
[McFetridge]
|
12184
|
Logical necessity overrules all other necessities
[McFetridge]
|
12180
|
Logical necessity requires that a valid argument be necessary
[McFetridge]
|
12183
|
It is only logical necessity if there is absolutely no sense in which it could be false
[McFetridge]
|
12192
|
The mark of logical necessity is deduction from any suppositions whatever
[McFetridge]
|
12189
|
Logical necessity involves a decision about usage, and is non-realist and non-cognitive
[Wright,C, by McFetridge]
|
14681
|
Logical necessity is free of constraints, and may accommodate all of S5 logic
[Salmon,N]
|
13394
|
Entailment does not result from mutual necessity; mutual necessity ensures entailment
[Jubien]
|
12185
|
Logical necessity is epistemic necessity, which is the old notion of a priori
[Edgington, by McFetridge]
|
10258
|
Logical modalities may be acceptable, because they are reducible to satisfaction in models
[Shapiro]
|
15417
|
Logical necessity has two sides - validity and demonstrability - which coincide in classical logic
[Burgess]
|
15419
|
General consensus is S5 for logical modality of validity, and S4 for proof
[Burgess]
|
12206
|
Broadly logical necessity (i.e. not necessarily formal logical necessity) is an epistemic notion
[Edgington]
|
12208
|
An argument is only valid if it is epistemically (a priori) necessary
[Edgington]
|
8260
|
Logical necessity can be 'strict' (laws), or 'narrow' (laws and definitions), or 'broad' (all logical worlds)
[Lowe]
|
16973
|
Explain logical necessity by logical consequence, or the other way around?
[Correia]
|
15085
|
'Broadly' logical necessities are derived (in a structure) entirely from the concepts
[Hale]
|
15088
|
Logical necessities are true in virtue of the nature of all logical concepts
[Hale]
|
13709
|
Logical truths must be necessary if anything is
[Sider]
|
19285
|
Logical necessity is something which is true, no matter what else is the case
[Hale]
|
19287
|
Maybe each type of logic has its own necessity, gradually becoming broader
[Hale]
|
18848
|
Something may be necessary because of logic, but is that therefore a special sort of necessity?
[Rosen]
|
9481
|
Logical necessitation is not a kind of necessity; George Orwell not being Eric Blair is not a real possibility
[Bird]
|
18478
|
Wittgenstein's plan to show there is only logical necessity failed, because of colours
[MacBride]
|
11084
|
Logical necessity is truth in all logically possible worlds, because of laws and concepts
[Hanna]
|
16042
|
The metaphysically and logically possible worlds are the same, so they are the same strength
[Bennett,K]
|
22150
|
Logical possibility needs the concepts of the proposition to be adequate
[Boulter]
|
18825
|
S5 is the logic of logical necessity
[Rumfitt]
|
12193
|
Logical necessity is when 'necessarily A' implies 'not-A is contradictory'
[Rumfitt]
|
12200
|
A logically necessary statement need not be a priori, as it could be unknowable
[Rumfitt]
|
12202
|
Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not
[Rumfitt]
|