Abstract
It is debatable under what conditions animal research is justified. Estimates of the number of animals used worldwide in research range from 41 to 100 million a year. ‘Animal research’ explores the complex issue of animal research, looking at issues such as: whether biomedical progress justifies harming nonconsenting research subjects; if so, whether there is a degree of harm to animal subjects beyond which it is unethical to go; how promising a proposed experiment must be to be ethically defensible; and how aggressively the research community should pursue alternatives to animal use. Animal research has played a part in biomedical progress, but it does not follow that it was necessary.