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Single Idea 14623

[filed under theme 10. Modality / B. Possibility / 8. Conditionals / a. Conditionals ]

Full Idea

The strict conditional implies the counterfactual conditional: □(A⊃B) ⊃ (A□→B) - suppose that A would not have held without B holding too; then if A had held, B would also have held.

Gist of Idea

Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B)

Source

Timothy Williamson (Modal Logic within Counterfactual Logic [2010], 1)

Book Ref

'Modality', ed/tr. Hale,B/Hoffman,A [OUP 2010], p.81


A Reaction

[He then adds a reading of his formula in terms of possible worlds] This sounds rather close to modus ponens. If A implies B, and A is actually the case, what have you got? B!


The 11 ideas with the same theme [general ideas about conditionals]:

Modal logic began with translation difficulties for 'If...then' [Lewis,CI, by Girle]
In nearby worlds where A is true, 'if A,B' is true or false if B is true or false [Stalnaker]
A conditional probability does not measure the probability of the truth of any proposition [Lewis, by Edgington]
Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington]
It is a mistake to think that conditionals are statements about how the world is [Edgington]
Three conditionals theories: Materialism (material conditional), Idealism (true=assertable), Nihilism (no truth) [Burgess]
It is doubtful whether the negation of a conditional has any clear meaning [Burgess]
Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B) [Williamson]
The point of conditionals is to show that one will accept modus ponens [Read]
The standard view of conditionals is that they are truth-functional [Read]
Some people even claim that conditionals do not express propositions [Read]