Abstract I contend that in Keats’ poetry, sleep-states (rather than dreams) become a site of erotic intensity and power-play. Contemporary scientific literature such as Robert Gray’s The Theory of Dreams suggested that in sleep, ‘the senses, though capable of being aroused, are closed in insensibility’. I draw upon this thinking to show that through depictions of sleep, Keats creates a paradoxical, knowing eroticism where the senses are aroused even though the will is suspended. It is not that the continuum between dreaming and waking is eroticised, but that sleep becomes a highly controlled private space that is insistently open to sensory suggestion. By focusing on sleep as an embodied sensory experience, I show how in Keats’s work the uncoupling of agency and feeling creates an eroticism which tests the lines between surrender and consent, will and desire. Taking a new angle on what Byron considered to be a tendency towards euphemistic prurience in Keats’s writing, this essay also proposes that Keats’s interest in the erotic vulnerability of bodies to one another creates a negative capability, and an ethics, highly sensitised to the way the boundaries between self and world are maintained.