Modern democracies regularly debate where religion and politics may appear in public life: who may fund religious activities, manage schools and hospitals, control public land, and sets the rules governing shared spaces. Yet, without a clear framework distinguishing the types of spaces where such expressions may occur, prohibitions and permissions remain inconsistent and contested, often with serious social and constitutional consequences.

This paper proposes a four-fold spatial model of institutional secularism, distinguishing 4 mutually exclusive and collectively exhaustive types of spaces: political, religious, private, and agoric (public circulation) spaces. Each is defined by ownership and primary function and carries distinct normative expectations regarding what expressions are institutionally permissible in each space. The model also introduces an “institutionalization test” to differentiate private, voluntary expression from state endorsement or institutional capture.

Applied to controversies ranging from religious symbols in state institutions and public funding of faith-based schools and hospitals, to political activity in religious venues and religious expression in shared spaces, the framework offers a logically coherent but also administratively workable method for determining what should and should not be permissible. The model therefore clarifies how secular, democratic constitutional orders can protect freedom of religion/irreligion while maintaining institutional neutrality.