Ideas from 'Conditionals' by Frank Jackson [2006], by Theme Structure
[found in 'Blackwell Guide to Philosophy of Language' (ed/tr Devitt,M/Hanley,R) [Blackwell 2006,0-631-23142-0]].
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5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
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14352
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'¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components
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10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional
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14360
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Possible worlds for subjunctives (and dispositions), and no-truth for indicatives?
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10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
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14353
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Modus ponens requires that A→B is F when A is T and B is F
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14354
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When A and B have the same truth value, A→B is true, because A→A is a logical truth
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14355
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(A&B)→A is a logical truth, even if antecedent false and consequent true, so it is T if A is F and B is T
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10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
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14358
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In the possible worlds account of conditionals, modus ponens and modus tollens are validated
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14359
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Only assertions have truth-values, and conditionals are not proper assertions
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14357
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Possible worlds account, unlike A⊃B, says nothing about when A is false
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10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
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14356
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We can't insist that A is relevant to B, as conditionals can express lack of relevance
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