The Legitimacy of Conductive Arguments: What Are the Logical Roles of Negative Considerations?

Abstract

Recent disputes on the negative considerations of conduction (conductive arguments) give rise to the legitimacy crisis of conduction. Adler (Argumentation 27:245–257, 2013) argues that the definition of conduction implies two incompatible claims which make conduction impossible. The crux of the impossibility of conduction argued by Adler can be summarized as a question: is it possible that the conclusions of conductive arguments are unqualified while the negative considerations remain viable? For this question, Xie & Xiong (Commentary on: J. Anthony Blair’s “are conductive arguments really not possible?”. Windsor, ON: OSSA, pp. 1–6, 2013) and Xie (Informal Logic 37:2–22, 2017) provide the rhetorical solution, which claims that the negative considerations only have the rhetorical roles (functions) so they are not viable at all in the arguments. On the contrary, Blair (Argumentation 30:109–128, 2016) presents the logical solution, which contends that the negative considerations have logical roles so they can weaken the strength of argument. This chapter first reconstructs Adler’s argument as well as the variant of it and then presents the criticism of the rhetorical and the logical solutions. Although Blair’s logical solution can resolve Adler’s challenge by transferring the qualification of conclusions to the qualification of argument strength, it does not completely defend the legitimacy of conduction. In order to better defend the legitimacy of conduction, the logical roles of the negative considerations are needed to be fully justified. In this connection, I provide a new proposal which focuses on the criteria of argument strength. From non-conductive defeasible arguments to conductive arguments, the criteria of argument strength will be changed from one item (i.e. “to what extent the positive considerations provide support for the conclusions”) to two items (i.e. “to what extent the positive considerations provide support for the conclusions” and “to what extent the positive considerations outweigh the negative considerations”). This change is caused by the existence of negative considerations, which shows the logical roles of negative considerations. Therefore, the legitimacy of conduction can be fully justified.