more from Dorothy Edgington

### Single Idea 14273

#### [catalogued under 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL]

Full Idea

Conditional Proof seems sound: 'From X and Y, it follows that Z. So from X it follows that if Y,Z'. Yet for no reading of 'if' which is stronger that the truth-functional reading is CP valid, at least if we accept ¬(A&¬B);A; therefore B.

Gist of Idea

Conditional Proof is only valid if we accept the truth-functional reading of 'if'

Source

Dorothy Edgington (Conditionals (Stanf) [2006], 2.2)

Book Reference

'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.5

A Reaction

See the section of ideas on Conditionals (filed under 'Modality') for a fuller picture of this issue. Edgington offers it as one of the main arguments in favour of the truth-functional reading of 'if' (though she rejects that reading).

Related Idea

Idea 14274
Inferring conditionals from disjunctions or negated conjunctions gives support to truth-functionalism **[Edgington]**