Combining Texts

Ideas for 'works', 'Necessary Beings' and 'On Perceptions'

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11 ideas

10. Modality / A. Necessity / 3. Types of Necessity
Absolute necessities are necessarily necessary [Hale]
     Full Idea: I argue that any absolute necessity is necessarily necessary.
     From: Bob Hale (Necessary Beings [2013], 05.5.2)
     A reaction: This requires the principle of S4 modal logic, that necessity implies necessary necessity. He argues that S5 is the logical of absolute necessity.
'Absolute necessity' is when there is no restriction on the things which necessitate p [Hale]
     Full Idea: The strength of the claim that p is 'absolutely necessary' derives from the fact that in its expression as a universally quantified counterfactual ('everything will necessitate p'), the quantifier ranges over all propositions whatever.
     From: Bob Hale (Necessary Beings [2013], 04.1)
     A reaction: Other philosophers don't seem to use the term 'absolute necessity', but it seems a useful concept, in contrast to conditional or local necessities. You can't buy chocolate on the sun.
Logical and metaphysical necessities differ in their vocabulary, and their underlying entities [Hale]
     Full Idea: The difference between logical and metaphysical necessities lies, not in the range of possibilities for which they hold, but - at the linguistic level - in the kind of vocabulary essential to their expression, and the kinds of entities that explain them.
     From: Bob Hale (Necessary Beings [2013], 04.5)
     A reaction: I don't think much of the idea that the difference is just linguistic, and I don't like the idea of 'entities' as grounding them. I see logical necessities as arising from natural deduction rules, and metaphysical ones coming from the nature of reality.
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is something which is true, no matter what else is the case [Hale]
     Full Idea: We can identify the belief that the proposition that p is logically necessary, where p may be of any logical form, with the belief that, no matter what else was the case, it would be true that p.
     From: Bob Hale (Necessary Beings [2013], 04.1)
     A reaction: I find this surprising. I take it that logical necessity must be the consequence of logic. That all squares have corners doesn't seem to be a matter of logic. But then he seems to expand logical necessity to include conceptual necessity. Why?
Maybe each type of logic has its own necessity, gradually becoming broader [Hale]
     Full Idea: We can distinguish between narrower and broader kinds of logical necessity. There are, for example, the logical necessities of propostional logic, those of first-order logic, and so on. Maybe they are necessities expressed using logical vocabulary.
     From: Bob Hale (Necessary Beings [2013], 04.5)
     A reaction: Hale goes on to prefer a view that embraces conceptual necessities. I think in philosophy we should designate the necessities according to their sources. This might clarify a currently rather confused situation. First-order includes propositional logic.
10. Modality / C. Sources of Modality / 1. Sources of Necessity
It seems that we cannot show that modal facts depend on non-modal facts [Hale]
     Full Idea: I think we may conclude that there is no significant version of modal supervenience which both commands acceptance and implies that all modal facts depend asymmetrically on non-modal ones.
     From: Bob Hale (Necessary Beings [2013], 03.4.3)
     A reaction: This is the conclusion of a sustained and careful discussion, recorded here for interest. I'm inclined to think that there are very few, if any, non-modal facts in the world, if those facts are accurately characterised.
10. Modality / C. Sources of Modality / 6. Necessity from Essence
The big challenge for essentialist views of modality is things having necessary existence [Hale]
     Full Idea: Whether the essentialist theory can account for all absolute necessities depends in part on whether the theory can explain the necessities of existence (of certain objects, properties and entities).
     From: Bob Hale (Necessary Beings [2013], Intro)
     A reaction: Hale has a Fregean commitment to all sorts of abstract objects, and then finds difficulty in explaining them from his essentialist viewpoint. His book didn't convince me. I'm more of a nominalist, me, so I sleep better at nights.
Essentialism doesn't explain necessity reductively; it explains all necessities in terms of a few basic natures [Hale]
     Full Idea: The point of the essentialist theory is not to provide a reductive explanation of necessities. It is, rather, to locate a base class of necessities - those which directly reflect the natures of things - in terms of which the remainder may be explained.
     From: Bob Hale (Necessary Beings [2013], 06.6)
     A reaction: My picture is of most of the necessities being directly explained by the natures of things, rather than a small core of natures generating all the derived ones. All the necessities of squares derive from the nature of the square.
If necessity derives from essences, how do we explain the necessary existence of essences? [Hale]
     Full Idea: If the essentialist theory of necessity is to be adequate, it must be able to explain how the existence of certain objects - such as the natural numbers - can itself be absolutely necessary.
     From: Bob Hale (Necessary Beings [2013], 07.1)
     A reaction: Hale and his neo-logicist pals think that numbers are 'objects', and they necessarily exist, so he obviously has a problem. I don't see any alternative for essentialists to treating the existing (and possible) natures as brute facts.
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
What are these worlds, that being true in all of them makes something necessary? [Hale]
     Full Idea: We need an explanation of what worlds are that makes clear why being true at all of them should be necessary and sufficient for being necessary (and true at one of them suffices for being possible).
     From: Bob Hale (Necessary Beings [2013], 03.3.2)
     A reaction: Hale is introducing combinatorial accounts of worlds, as one possible answer to this. Hale observes that all the worlds might be identical to our world. It is always assumed that the worlds are hugely varied. But maybe worlds are constrained.
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds make every proposition true or false, which endorses classical logic [Hale]
     Full Idea: The standard conception of worlds incorporates the assumption of bivalence - every proposition is either true or false. But it is infelicitous to build into one's basic semantic machinery a principle endorsing classical logic against its rivals.
     From: Bob Hale (Necessary Beings [2013], 10.3)
     A reaction: No wonder Dummett (with his intuitionist logic) immediately spurned possible worlds. This objection must be central to many recent thinkers who have begun to doubt possible worlds. I heard Kit Fine say 'always kick possible worlds where you can'.