The Necessary Existence of Inference-Claims

Abstract

In (2018) Gilbert Plumer argues against the existence of inference-claims on the grounds that they lead to the kind of vicious infinite regress illustrated in Carroll’s famous Achilles and the Tortoise paper (Carroll 1895). In Plumer’s view, it is not simply that neither arguments nor arguers do make inference-claims, but that they can’t do so, on pain of this regress. In further unpublished work Plumer has generalized from this result: it is a mistake to include reference to standards of argument assessment within the content of the argument. Inference-claims (i.e., sufficiency-claims) do not exist, and neither do relevance-claims or acceptability-claims, and all for much the same reason. I will argue that his arguments fail to show that inference-claims do not exist, because the regresses they lead to either are not vicious, not infinite, or can be avoided. Then I hope to show, on the grounds of what I call the ‘completeness’ of the argument, that inference-claims not only do exist but that they must exist. This is not to say that inference-claims are necessarily asserted in an act of arguing, but asserting them would not lead to the kind of harmful consequences Plumer supposes, any more than their mere existence would.