The earliest known products of human imagination appear to express a primordial concern and struggle with thoughts of dying and of death and mortality. I argue that the structures and processes of imagination evolved in that struggle, in response to debilitating anxieties and fearful states that would accompany an incipient awareness of mortality. Imagination evolved to find that which would make the nascent apprehension of death more bearable, to engage in a search for alternative perceptions of death: a search that was beyond the capability of the external senses. I argue that imagination evolved as flight and fight adaptations in response to debilitating fears that paralleled an emerging foreknowledge of death. Imagination, and symbolic language to express its perceptions, would eventually lead to religious behavior and the development of cultural supports. Although highly speculative, my argument draws on recent brain studies, and on anthropology, psychology, and linguistics.