more from this thinker     |     more from this text


Single Idea 15081

[filed under theme 10. Modality / A. Necessity / 3. Types of Necessity ]

Full Idea

One type of necessity may be said to be 'stronger' than another when the first always entails the second, but not conversely. This will obtain only if the possibility of the first is weaker than the possibility of the second.

Gist of Idea

A strong necessity entails a weaker one, but not conversely; possibilities go the other way

Source

Bob Hale (Absolute Necessities [1996], 1)

Book Ref

-: 'Philosophical Perspectives' [-], p.94


A Reaction

Thus we would normally say that if something is logically necessary (a very strong claim) then it will have to be naturally necessary. If something is naturally possible, then clearly it will have to be logically possible. Sounds OK.


The 26 ideas with the same theme [different ways in which things must be]:

A stone travels upwards by a forced necessity, and downwards by natural necessity [Aristotle]
Carneades distinguished logical from causal necessity, when talking of future events [Long on Carneades]
Necessity is physical, logical, mathematical or moral [Schopenhauer, by Janaway]
The only necessity is logical necessity [Wittgenstein]
Necessities are distinguished by their grounds, not their different modalities [Ellis]
We should not multiply senses of necessity beyond necessity [Jackson]
There is 'absolute' necessity (implied by all propositions) and 'relative' necessity (from what is given) [Harré/Madden]
Strong necessity is always true; weak necessity is cannot be false [Stalnaker]
Logical possibility contains metaphysical possibility, which contains nomological possibility [Salmon,N]
The three basic types of necessity are metaphysical, natural and normative [Fine,K]
'Conceptual' necessity is narrow logical necessity, true because of concepts and logical laws [Lowe]
Logical necessities, based on laws of logic, are a proper sub-class of metaphysical necessities [Lowe]
Maybe not-p is logically possible, but p is metaphysically necessary, so the latter is not absolute [Hale]
A strong necessity entails a weaker one, but not conversely; possibilities go the other way [Hale]
'Relative' necessity is just a logical consequence of some statements ('strong' if they are all true) [Hale]
'Strong' necessity in all possible worlds; 'weak' necessity in the worlds where the relevant objects exist [Sider]
'Absolute necessity' is when there is no restriction on the things which necessitate p [Hale]
Logical and metaphysical necessities differ in their vocabulary, and their underlying entities [Hale]
Absolute necessities are necessarily necessary [Hale]
Analytic truths are divided into logically and conceptually necessary [Girle]
Is 'events have causes' analytic a priori, synthetic a posteriori, or synthetic a priori? [Baggini /Fosl]
If the laws necessarily imply p, that doesn't give a new 'nomological' necessity [Bird]
Relevant necessity is always true for some situation (not all situations) [Beall/Restall]
Physical possibility is part of metaphysical possibility which is part of logical possibility [Rami]
Superficial necessity is true in all worlds; deep necessity is thus true, no matter which world is actual [Schroeter]
A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A]