Critical Notice of Douglas Walton's Slippery Slope Arguments

Abstract

The book's main contention is that, far from being necessarily fallacious, slippery slope arguments are often acceptable in a discussion, shifting the burden of proof. Against this approach, I argue that slippery slope arguments are ensuant on the gap between a continuous underlying series of characteristics - the input - and a discontinuous two-valued output. Law as usually conceived only seldom allows of middle courses, and is prone to all-or-nothing attitudes. I advocate a gradualistic solution. All essential properties involved in those arguments admit of degrees. Many actions can be both praiseworthy up to a point and yet also reprehensible to some extent. We ought to overcome the two-valuedness of our juridical systems, replacing it, in so far as it is feasible, with systems of scales. Truth admits of degrees. A reasonable approach to our moral and legal judgments and practices would entail a step-by-step departure from rigid dichotomies, favouring a more gradualistic approach. This approach, needed in both logic and juridical doctrine, is compatible with the inner patterns of our thought process. Walton does nor raise those questions since he tries to implement a purely pragmatic approach.