Abstract

Philosophical theories of various sorts rely on there being robust boundaries between kinds of content. One way of drawing such boundaries is to place them between subject matters, like physics and aesthetics, and the domains of sentences falling within them. Yet contemporary literature exploring the nature of discourse domains is relatively sparse. The goal of this paper is to articulate the core features of discourse domains for them to provide the sought-after explanatory utility of establishing robust boundaries between discursive contents. Analyzing the role that discourse domains have under alethic theories yields valuable information about the ways in which domains subject themselves to being defined and how alethic theories can explain the variability of truth-aptness or truth across sentences from distinct domains. The concluding argument is that because of certain issues with defining domains as unambiguous classes of sentences when individuated on the grounds of topical subject matters, philosophers should consider a commitment to indeterminism about the extensions of fundamental domains. According to this view, although domains can be defined as relatively well-individuated classes of sentences based on topical distinctions, the temporal development of our conceptual frameworks and the phenomenon of mixed content compromise our ability to definitively account for the domain membership of all truth-apt sentences. Such an indeterminacy argument is relevant for all who rely on there being robust boundaries between topically individuated discursive contents.