The sublime in chemical terms transforms the solid, or earth, into the gaseous, or air. The sublime for Zoë Sofoulis is always shadowed by slime, which she encapsulates in the parenthetical portmanteau s(ub)lime. Slime is the secret of the sublime. This chapter traces: the sublime in work of Longinus and slime in Dante’s Inferno; through the sublime in the work of Kant and Burke, and slime in Sartre’s Being and Nothingness; to the s(ub)lime in late twentieth-century critical theory, including Lyotard’s, Berman’s, and Eagleton’s accounts of aesthetics and modernity. The sublime is central to western aesthetics, especially in the modern period. Around the name of the sublime, Lyotard remarks, “modernity triumphed,” not least over wetlands in the short term by draining, filling, impounding, or embanking them, ironically using machines powered by fossil fuels from relict wetlands. The fossilised remains of swamps are sublim(at)ed into ‘gas’ to power machines and vehicles with steam, internal combustion, and jet engines in what Mumford called “carboniferous capitalism” that gave rise to the age of global boiling and the Anthropobscene. This chapter traces this irony, as well as critiquing the gender politics and ecoculture of the masculinist sublime and the misogynist feminisation of slime.