Ewald is the first author to present a Darwinian perspective on infectious disease, which opens up a whole new approach to health science, one that emphasizes new possibilities for combatting deadly diseases like malaria, tuberculosis, and AIDS. Taking an evolutionary approach, Ewald views disease-producing bacteria and viruses as parasites and explains the history of disease as a host-parasite relationship, one which can evolve in many different effects on the host population. He explains why the agents of cholera, malaria, and AIDS are so dangerous and why treatment of virtually all diseases would be improved by applications of evolutionary principles. This merging of evolutionary biology with health sciences offers a new dimension to policy-making in the health sciences by identifying interventions that will force infectious organisms to evolve toward a benign state, to subdue the plagues of the past and help us to avert the plagues of the future. A wholly readable account of an enthralling and important subject of concern to us all.