The use of nonhuman animals in biomedical research: necessity and justification.

Discourse about the use of animals in biomedical research usually focuses on two issues: its empirical and moral use. The empirical issue asks whether the use of nonhumans in experiments is required in order to get data. The moral issue asks whether the use of nonhumans can be defended as matter of ethical theory. Although the use of animals in research may involve a plausible necessity claim, no moral justification exists for using nonhumans in situations in which we would not use humans.