Woods, Michael (Wiggins, David, ed.) - Conditionals

Conditional statements appear to involve a form of sentence composition, but one that is non-truth-functional (that is, the truth-value of the conditional sentence appears not always to be determined by the truth-values of its parts). However, whether these appearances are correct is, for a number of reasons, rather hard to determine. One thing that gives rise to doubts about the truth-functionality of conditional statements is that it seems so easy to construct sentences which have no natural use but which would have to be counted as expressing truths if conditionals are understood truth-functionally.