Iffiness

Abstract

How do ordinary indicative conditionals manage to convey conditional information, information about what might or must be if such-and-such is or turns out to be the case? An old school thesis is that they do this by expressing something iffy: ordinary indicatives express a two-place conditional operator and that is how they convey conditional information. How indicatives interact with epistemic modals seems to be an argument against iffiness and for the new school thesis that if -clauses are merely devices for restricting the domains of other operators. I will make the trouble both clear and general, and then explore a way out for fans of iffiness. Keywords

A Counterexample to Modus Tollens

“…So why think that it would together with a triviality? Thus the inference from (10) and (11) to (1) is invalid; and similarly for any argument of the same schematic form.…”

“…Now to come to the difficulty, fix your attention upon (10). Let us consider an MT inference involving it.…”

“…This style of argument certainly works in principle. 11 But the trouble is, if there are two scopal orders logically possible for sentences like (P1), it seems that they yield semantically 10 See [18]. For further discussion see [35].…”

“…And there is already solid evidence that modal operators are in general sensitive to some such semantically shiftable parameter; indeed, that has claim to being the standard view of the matter. 10 So, bracketing some independent evidence, appealing to context-sensitivity and context-shifting here is quite unmotivated.…”

“…Or to put essentially the same thought in less loaded terms, the idea is that the likely in (P1) is in some sense semantically evaluated with respect to more 7 One valid instance occurred in the first paragraph of this paper, when I concluded that MT is not generally valid. 8 See, inter alia, [9,10,15,30,35,37] for relevant work and the appendix for explicit examples. 9 Could one retreat to the claim that MT should be construed as a generalization only about bare conditionals?…”