more on this theme     |     more from this thinker

Single Idea 19287

[filed under theme 10. Modality / A. Necessity / 6. Logical Necessity ]

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.

Gist of Idea

Maybe each type of logic has its own necessity, gradually becoming broader

Source

Bob Hale (Necessary Beings [2013], 04.5)

Book Ref

Hale,Bob: 'Necessary Beings' [OUP 2013], p.114

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.

The 23 ideas from 'Necessary Beings'

19275 You cannot understand what exists without understanding possibility and necessity [Hale]
19276 The big challenge for essentialist views of modality is things having necessary existence [Hale]
19278 There is no gap between a fact that p, and it is true that p; so we only have the truth-condtions for p [Hale]
19279 What are these worlds, that being true in all of them makes something necessary? [Hale]
19281 Interesting supervenience must characterise the base quite differently from what supervenes on it [Hale]
19282 It seems that we cannot show that modal facts depend on non-modal facts [Hale]
19286 'Absolute necessity' is when there is no restriction on the things which necessitate p [Hale]
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]
19288 Logical and metaphysical necessities differ in their vocabulary, and their underlying entities [Hale]
19289 Maybe conventionalism applies to meaning, but not to the truth of propositions expressed [Hale]
19290 Absolute necessities are necessarily necessary [Hale]
19291 A canonical defintion specifies the type of thing, and what distinguish this specimen [Hale]
19293 Essentialism doesn't explain necessity reductively; it explains all necessities in terms of a few basic natures [Hale]
19294 If necessity derives from essences, how do we explain the necessary existence of essences? [Hale]
19295 Add Hume's principle to logic, to get numbers; arithmetic truths rest on the nature of the numbers [Hale]
19296 If second-order variables range over sets, those are just objects; properties and relations aren't sets [Hale]
19297 The two Barcan principles are easily proved in fairly basic modal logic [Hale]
19298 Unlike axiom proofs, natural deduction proofs needn't focus on logical truths and theorems [Hale]
19299 Possible worlds make every proposition true or false, which endorses classical logic [Hale]
19300 The molecules may explain the water, but they are not what 'water' means [Hale]
19301 With a negative free logic, we can dispense with the Barcan formulae [Hale]
19302 If a chair could be made of slightly different material, that could lead to big changes [Hale]