Truthmakers, paradox and plausibility

In a series of articles in this journal, Dan López De Sa and Elia Zardini (2006, 2007) (forthwith ‘LSZ’) have argued that several theorists have recently employed instances of paradoxical reasoning, while failing to see its problematic nature because it does not immediately (or obviously) yield inconsistency. In contrast, LSZ claim that resultant inconsistency is not a necessary condition for paradoxicality. According to them (2007: 246), ‘[w]hat really seems to be the essence [of the notion of ‘paradox’] is that, despite the apparent validity of the argument, the premises do not rationally support the conclusion’. It is our contention here that, even given their broader understanding of paradox, LSZ’s arguments fail to undermine the instances of reasoning they attack, either because they fail to see everything that is at work in that reasoning, or because they misunderstand what it is that the reasoning aims to show. With their broader reading of ‘paradox’ in hand, LSZ argue that a number of philosophers – principally, Roy Sorensen, but also the present authors (given our attack on Sorensen (2001)) and several others – are guilty of wielding ‘paradoxical’ arguments, and, what is worse, of using them in the service of establishing substantial philosophical claims. They contend that we must reject such ‘paradoxical’ reasoning and that this is so, even if the theses these theorists aim to establish are true. As we will show, LSZ’s attacks fail to establish these cases of reasoning as paradoxical (even in their broader sense). However, this result does not offer any support to the idea that it is possible to establish substantive philosophical claims through nothing but abstract formal reasoning. This is because at least part of what must be addressed in the cases that LSZ consider is how we should think about the sorts of philosophical arguments they aim to depose. In clarifying this below, we briefly highlight the notion of a plausibility argument, namely, an argument made in support of a thesis, though without the aim of a (formal) proof. We take this kind of argument to be what is really at work in most of the cases LSZ consider, along with much of contemporary philosophy. The plan is as follows. In x1, we consider some of the background for Sorensen’s epistemicism regarding certain indeterminate cases. Then, in x2, we explain his general approach to certain puzzling semantic cases and the assumptions that drive it. In x3, we explain Sorensen’s position on the case of central concern in LSZ’s argument, and in x4, we review their criticism of Sorensen’s reasoning. In xx5–6, we critically evaluate LSZ’s attack on