 In defence of contraposition, it might be argued that in the case of causal claims there is at least a weak form of contraposition that is valid. Gomes proposes (Gomes 2009) that where ‘A’ is claimed to be a causally sufficient condition for ‘B’, or ‘B’ a causally necessary condition of ‘A’, then some form of reciprocity between the two kinds of conditions holds, and so some version of contraposition will be valid. Going back to example (ii), suppose we read this as stating a causal condition—that your touching me would cause me to scream. Gomes suggests that ‘A’ denotes a sufficient cause of B, provided that (1) ‘A’ specifies the occurrence of an event that would cause another event ‘B’, and does this by (2) stating a condition the truth of which is sufficient for inferring the truth of ‘B’. In such a case, we could further maintain that ‘B’, in turn, denotes a necessary effect of ‘A’, meaning that the truth of B provides a necessary condition for the truth of A (Gomes 2009, 377–9). It is notable that Crupi and Iacona’s evidential conditional also preserves contraposition, which they claim as a distinctive feature of of their analysis, based on their understanding that “provides evidence for” is another way of saying “supports” (section 6 of Crupi and Iacona 2020). For them, if Solange’s presence provides evidence for the seminar being good (see (xiii) above), then the seminar’s not being good is evidence of Solange’s absence. They—like Gomes (2019)—thus reject Downing’s (1975) general scepticism about contraposition. Wilson, by contrast, argues that the seminar not being good might also be a reason why Solange does not attend. But this, he claims, “saves only the appearance of contraposition” (Wilson 1979, 274–5).