Semantics: Possible worlds with Logical, Epistemic, and Deontic Modality?

Question

I understand each of the Modalities, but I'm not sure how they relate to possible worlds. Is the following correct? Is it failing to hit the nail on the head? (Are my conclusions in the parenthesis also correct?)

Logical Necessity: fact about the real world
Logical Possibility: doesn't describe the real world
(Logical Modality applies to the real world... AND possible worlds?)

Epistemic Necessity: applies to possible worlds, but implies the real world
Epistemic Possibility: applies to possible worlds
(Epistemic Modality applies to possible worlds.)

Deontic Necessity: what is required in a perfect obedience world
Deontic Possibility: what is allowed in a perfect obedience world
(Deontic Modality does not apply to real or possible worlds, only perfect obedience worlds defined by a set of rules or code of behavior.)

Thank you! If you were able to answer my question, I'd appreciate it if you'd look at the other questions I'm asking today!
(There's no good Yahoo category for Semantics or even Linguistics...)

Answer 1

Necessity is shorthand for truth in every possible world; possibility, true in at least one possible world (or it's not necessarily false in every world).

A logical necessity is a tautology, like the law of non-contradiction. In every world where logic holds, certain propositions will never be false. [Because there are, arguably, possible worlds where logic does not hold.]

A logical possibility is just a contingent proposition like "Pa": Alfred is on the phone. There's no contradiction in the assertionitself. You have to check the domain of discourse to see if it's true.

Epistemic anything regards what we can know. An epistepic necessity would be, say, the necessary conditions of cognition, if knowledge requires consciousness. Whereas an epistemic possibility could lead us to knowledge or not. (guessing.)

I have no background in deontic modality. Looks fun though :)

Answer 2

Should I report that guy for abuse or what.
....

Now for your request: The descriptions you give are correct to my recollected memory for their word definitions, but I would care not to treat as them as deotologically valid; words like 'real' are usable to differentiate unreal from other unreal, e.g. if it is not a real X, is it a plastic X, a halucinated X, a forged X or counterfeit X, or not yet certified as a proper X, or another kind of unreal.....

Logic as its own subject is internally unified with itself. 'Logical' as an adjective word class describes deontic logicallity, but a logic participle may describe a determinant for deontic logicallity, e,g, are they educated in a rule for logic or is logic principle contingent (a belief)

.http://www.marxists.org/reference/archive/hegel/works/ph/phc2b1b.htm

'The Phenomenology of Mind

C: Free Concrete Mind: (BB) Spirit

B. The Spirit in Self-Estrangement
I. b. Belief and Pure Insight (1)
Φ 527. THE spiritual condition of self-estrangement exists in the sphere of culture as a fact. But since this whole has become estranged from itself, there lies beyond this sphere the nonactual realm of pure consciousness, of thought. Its content consists of what has been reduced purely to thought, its absolute element is thinking. Since, however, thinking is in the first instance the element of this world, consciousness has merely these thoughts, but it does not as yet think them or does not know that they are thoughts: to consciousness they appear in the form of presentations, they are objects in the form of ideas. For it comes out of the sphere of actuality into that of pure consciousness, but is itself still to all intents and purposes in the sphere of actuality with the determinateness that implies. The conscious state of contrition and abasement is still essentially and inherently the self-identity of pure consciousness, not as a fact that itself is aware of but only as presented to us who are considering its condition.'

.http://www.marxists.org/reference/archive/hegel/works/ph/phc2b1b.htm