The Role of Ostension in Visual Argumentation

Abstract

I argue that images can figure in arguments as objects of ostension. Typically ostensive acts take place as parts of a directive speech-act (e.g. the speech-act conveyed by Look at O). In the cases described below directives work as premises in an argument scheme whose warrant can be stated in the form “perception of the ostended object (or event) counts as a reason for the conclusion”. These are heterogeneous or multimodal arguments making use of both verbal and visual resources. Images play a substantial role in such arguments from ostension since they furnish a sort material evidence that words cannot convey.