Assertion as a Normative Act : how Assertoric Speech Shapes Social Reality

The thesis focuses on the conception of assertion as a normative act and attempts to give an explanation of.the emergence of the normativity of assertion compatible with a realistic description of ordinary speakers. The model I propose sees the shared normative standards of assertion as a reflection of coordination equilibria which allow humans to communicate through verbal language and establish conventional meanings attached to sentences. Within this picture, the normativity of assertion is dependent upon but not reducible to the evolutionary process of shaping language meaning. It is not reducible because while evolutionary signal theory explains how one model of language interaction is actualized, normativity reflects the attempt to promote said model amongst the different possible ones. The thesis goes on to inquire what happens to normative standards when the cooperative context giving birth to the coordination model is undermined. The verdict is that lack of cooperativity causes a decline in accountability for truth and the very normative force of assertion itself. Two main case-studies are brought up: the phenomenon of dialectical obstructionism and the phenomenon of post-truth rhetoric in polarized political debate. I show how in both cases the very speech-act of assertion is undermined by a context where language is no longer used for the mutual goal of exchanging true information, but rather to promote the narrative of one particular faction at the expense of truth and accountability.