Reveals the fragility of basic scientific concepts through the unstable relationship between viruses and life, calling for a deconstructive reading to grapple with their theoretical and political effects. Virality Vitality explores the history and present of the life sciences and virology, focusing on moments of disruption that reveal the instability of the most basic concepts guiding scientific knowledge and their practical or political consequences. From their "discovery" to present-day experiments in synthetic virology, viruses have given rise to upheavals in our models of life because of the difficulty of rigorously distinguishing life from virus, self from other. The virus has been compared to a gene, to an agent of life's heredity and immunity, and we humans depend on the fossils of ancient viral infections in our genome in order to bear children. Can a parasite give birth to its host? To interpret the nonoppositional relationship of virality and vitality, this book draws on the work of Jacques Derrida and the growing field of biodeconstruction that has emerged from his posthumously published work on genetics. In turn, Virality Vitality suggests a novel approach to questions of the agency of "matter" or the "nonhuman," often raised in Anthropocene studies, the material turn, and ecocriticism. Nothing is more natural than the artificiality of the borders drawn, maintained, and displaced by the living and their viruses, by virality-vitality. The inscription of these borders remains to be read, and thus deconstructive textuality is anything but opposed to the sciences and what they call life.