This dissertation investigates the relationship of humans to their planet through the framework of Earth imaginaries: the implicit, shared background understandings of Earth, carried in images, metaphors, and stories, that make sense of practices including Earth photography, climate science and engineering, and the extension of rights to nature. The dominant planetary imaginary figures a promethean human-planet relation of human exceptionalism, mastery, and stewardship that is premised on the disavowal of terrestriality, the constitutive earthliness of human being. The opposing Earth community imaginary, sustained by the transnational Rights of Nature movement, avows a figuration of terrestriality through declaration. The philosophical encounter between these imaginaries is investigated through the problem space of Gaia, which is characterized by the displacement of ontological reflection about planetary being by systems understandings of the planet. However, instead of adjudicating between these imaginaries, I propose attending to their meeting at sites of confluence: where the disavowal of terrestriality meets its avowal. Reading the self-declaration of the personhood of the Mutehekau Shipu/Magpie River alongside Jacques Rancière’s theory of politics, I argue that confluential politics can emerge at these confluence sites, generating the more-than-human collective political subjects whose emplaced practices refigure the human-planet relation.