Examining the ideas and attitudes that encourage scientists to experiment on living creatures, what their justifications are, and how these have changed over time. Experimentation on animals—particularly humans—is often assumed to be a uniquely modern phenomenon. But the ideas and attitudes that encourage biological and medical scientists to experiment on living creatures date from the earliest expressions of Western thought. In Experimenting with Humans and Animals, Anita Guerrini looks at the history of these practices and examines the philosophical and ethical arguments that justified them. Guerrini discusses key historical episodes in the use of living beings in science and medicine, including the discovery of blood circulation, the development of smallpox and polio vaccines, and recent research in genetics, ecology, and animal behavior. She also explores the rise of the antivivisection movement in Victorian England, the modern animal rights movement, and current debates over gene therapy and genetically engineered animals. We learn how perceptions and understandings of human and animal pain have changed; how ideas of class, race, and gender have defined the human research subject; and that the ethical values of science seldom stray far from the society in which scientists live and work. Thoroughly rewritten and updated, with new material in every chapter, the book emphasizes a broader understanding of experimentation and adds material on gene therapy, self-experimentation, and prisoners and slaves as experimental subjects. A new chapter brings the story up to the present while reflecting on the current regulatory scene, new developments in science, and emerging genomics. Experimenting with Humans and Animals offers readers a context within which to understand more fully the responsibility we all bear for the suffering inflicted on other living beings in the name of scientific knowledge.