While the traditional vertical understanding of rights remains rooted in an older liberalism, the horizontal model possesses affinities with republican thought. This chapter makes these connections between constitutional practice and some of the core texts in the history of political thought. In addition to different understandings of the relationship between spheres, or the individual and community, liberal and republican thought generally conceive of liberty differently, a distinction that also maps onto the vertical and horizontal models in important ways. Rights in a horizontal understanding take on a new significance as more than mere rights, but ends as well, that potentially implicate the polity as a whole. Thus, horizontal application gives rise to new calls for parity between public and private spaces, which, in turn, amounts to a new source for understanding the duties of private actors. Such concepts as the common good and duty, integral to republican thought, come to the fore and offer a baseline for conceptualizing the parity and duties to which horizontal application gives rise. The chapter illustrates how these republican concepts occur in the context of actual cases and larger constitutional discourses, drawing examples from Germany, India, and South Africa.