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
'', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components
10. Modality / B. Possibility / 8. Conditionals / b. Types of conditional
Possible worlds for subjunctives (and dispositions), and no-truth for indicatives?
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
When A and B have the same truth value, A→B is true, because A→A is a logical truth
(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
Modus ponens requires that A→B is F when A is T and B is F
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
Possible worlds account, unlike A⊃B, says nothing about when A is false
In the possible worlds account of conditionals, modus ponens and modus tollens are validated
Only assertions have truth-values, and conditionals are not proper assertions
10. Modality / B. Possibility / 8. Conditionals / f. Pragmatics of conditionals
We can't insist that A is relevant to B, as conditionals can express lack of relevance