Title

On deductivism : a critical survey of deductivism in informal logic

Date of Award

2007

Degree Type

Thesis

Degree Name

M.A.

Department

Philosophy

Rights

CC BY-NC-ND 4.0

Abstract

The aim of this thesis is to understand and critically evaluate deductivism as a theory of inferential sufficiency in informal logic. I distinguish three different types of deductivism: strong normative deductivism, weak normative deductivism, and reconstructive deductivism. I also discuss some potential justificatory strategies that might be invoked in an attempt to justify strong normative deductivism and reconstructive deductivism. I apply this categorization scheme to develop an interpretation of Leo Groarke's version of reconstructive deductivism. I then evaluate some of the criticisms of deductivism raised in the informal logic literature. I focus in particular on the criticisms of Ralph Johnson and Trudy Govier. I follow up this evaluation by raising some problems for the justificatory strategies used to support deductivism. I also show how these problems apply to Groarke's reconstructive deductivism.