What can we learn about the history and culture of modernity when viewed from the seemingly marginal perspective of bacteriology? And how does this science itself become culturally readable when the narrow scope of traditional history of science is transcended in favor of a history of knowledge? The texts gathered in this volume demonstrate how bacteriology as a science could only emerge under very specific modern conditions—discourses, institutions, and techniques—and they examine how bacteriology, with its concepts and analytical methods, has profoundly shaped the modern understanding of body and disease, as well as boundaries and migration movements, nations, and wars. It becomes clear that the scientifically grounded discourse of the "invisible enemy" by bacteriologists became a central theme in the 20th century.