Combining Texts

All the ideas for 'Logical Necessity: Some Issues', 'Exigency to Exist in Essences' and 'The Concept of Logical Consequence'

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17 ideas

5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Split out the logical vocabulary, make an assignment to the rest. It's logical if premises and conclusion match [Tarski, by Rumfitt]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
X follows from sentences K iff every model of K also models X [Tarski]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'model' is a sequence of objects which satisfies a complete set of sentential functions [Tarski]
7. Existence / A. Nature of Existence / 5. Reason for Existence
Possibles demand existence, so as many of them as possible must actually exist [Leibniz]
God's sufficient reason for choosing reality is in the fitness or perfection of possibilities [Leibniz]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity overrules all other necessities [McFetridge]
The fundamental case of logical necessity is the valid conclusion of an inference [McFetridge, by Hale]
In the McFetridge view, logical necessity means a consequent must be true if the antecedent is [McFetridge, by Hale]
Logical necessity requires that a valid argument be necessary [McFetridge]
Traditionally, logical necessity is the strongest, and entails any other necessities [McFetridge]
It is only logical necessity if there is absolutely no sense in which it could be false [McFetridge]
The mark of logical necessity is deduction from any suppositions whatever [McFetridge]
10. Modality / B. Possibility / 2. Epistemic possibility
We assert epistemic possibility without commitment to logical possibility [McFetridge]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Objectual modal realists believe in possible worlds; non-objectual ones rest it on the actual world [McFetridge]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal realists hold that necessities and possibilities are part of the totality of facts [McFetridge]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
The actual universe is the richest composite of what is possible [Leibniz]
19. Language / E. Analyticity / 1. Analytic Propositions
Sentences are 'analytical' if every sequence of objects models them [Tarski]