Another dubious counter-example to conditional transitivity
Edward Jonathan Lowe · Analysis · 2009
Current orthodoxy has it that hypothetical syllogism is not a valid form of inference for ordinary-language counterfactuals, but since this claim continues to be questioned by some philosophers including myself (see, for example, Lowe 1983, 1990 and 1995), the defenders of orthodoxy continue to construct what they often suppose to be knock-down counter-examples to the transitivity of such conditionals, that is, to the thesis that the following is a valid inference-pattern where such conditionals are concerned: A □→ B, B □→ C, therefore A □→ C Morreau’s putative counter-example may be set out as follows, with a few insignificant modifications. Suppose that, in an ordinary conversation, someone were to assert both and One might suppose that from (1) and (2) one could validly infer However, uncontroversial though (3) might be in these circumstances, the context of utterance might – or so Morreau contends – very well be one in which the speaker would also be happy to assert because, as Morreau puts it, ‘it is understood that this is not the season for thunderstorms’ (447). But, he contends, from (1) and (4) we are not entitled to infer (Why not? Morreau doesn’t say, but evidently he must presume that (5) is necessarily false. Against that, it might be urged that (5) is just a flamboyant way of affirming that there wouldn’t – indeed, couldn’t – have been a thunderstorm in these circumstances: an idea that fits quite well with a point that I am about to make.) And yet, if hypothetical syllogism were valid for such conditionals, this is precisely what we would be entitled to infer. So, it seems, we should conclude that it is not valid, despite the fact that (3) seems to follow from (1) and (2).