Abstract In this article we develop a social theoretical conception of the boundaries of public speech. There is a vivid debate concerning supposed shifts of these boundaries. Some argue that boundaries are contracting, causing formerly accepted conservative positions to be excluded as extremist. Others argue that boundaries are expanding and shifting to the right, causing formerly unspeakable far-right ideology to be normalized. Unfortunately, there is a lack of long-term empirical studies that systematically compare sayability boundaries over the decades, making it difficult to validate or invalidate either of these contradicting claims. The social theoretical conception of the boundaries of public speech developed in this article is designed to enable such empirical research. After naming the relevant strands of research literature and evaluating their contribution to the research of sayability boundaries, we develop our conception of discourse and its boundaries. First, we deploy conceptions from Foucault and Offe to distinguish different types of boundaries, with normative boundaries being the ones that are most pertinent to current debates. The concept of normative boundaries refers to discursive rules marking certain statements as socially undesirable. Second, we argue that normative boundaries should not be conceptualized as a single line separating a normatively sayable inside from a normatively unsayable outside. Instead, we devise a tiered system of six normative boundaries creating seven degrees of normative sayability, which differ from one social context to another. Third, we turn toward the ways in which boundaries are anchored in social practice and social structures distinguishing the subjective, the intersubjective, and the objectified level, as well as different degrees of formalization. Finally, we outline pathways through which this conception can be used in empirical research that builds on and goes beyond the existing research literature.
Biskamp et al. (Mon,) studied this question.