This chapter considers the constructions of spiritual anguish and forms of healing as figurations of darkness and light inspired by medical understandings of stroke, paralysis, and aphasia in the early to mid-nineteenth century. It suggests that Tennyson’s elegy learns much from the brain sciences which inspired and drew upon theories of natural development and corporeal materialism to understand the complex causes and different forms of apoplexy (stroke). Varying professional opinions on the causes of Arthur Henry Hallam’s death referred to existing theories on the causes of cerebral haemorrhage, which could be both sudden and forewarned and result in various forms of paralysis including aphasia or ‘speech blindness’. It is these ideas which inspired Tennyson’s famous images of an infant crying in the night—the expressions of a crisis of faith which was experienced, certainly in the early stages of the poem’s creation, as a form of darkness. Contrary to a popular critical opinion that Tennyson saw there to be a firm divide between the materiality of the body and the transcendence of the soul, this chapter argues that models of apoplexy and aphasia inspired an image of matter as the early stages of a human capacity for spiritual healing.