In "Trends in Animal Research," Madhusree Mukerjee reviews the long-standing debate over the use of animals in research. In this article, he states, "increased concern for animals, among scientists as well as the public, is changing the ways in which animals are used for research and safety training (Mukerjee, 1997)." Although it is impossible to deny that vast improvements in the human condition have been the direct result of research using animals, many people throughout history have questioned its appropriateness.

The philosophical foundation underlying the debate about using animals in research can be linked to Aristotle's distinctions between three types of souls (Shanks, pp. 6-7). A vegetative soul has a simple capacity for life. Animals, containing a sensitive soul, have the capacity for sensation along with the capacity for life. The rational soul, the kind attributed to humans, has a capacity for thought, sensation, and life (Shanks, p. 6). The debate surrounding the use of animals in research has evolved over time, and has directly affected the way in which animals are cared for and used in research. Neither support for nor opposition to animals in research is new.

In the 1500s, Andrea Vesalis wrote the first anatomy text, which showed anatomical similarities between humans and animals (Shanks, pp. 29-33). The use of animals in research to expand the knowledge of human physiology continued into the 1800s when in 1885 Louis Pasteur directly applied animal research to reduce human suffering (Rudacille, pp. 21-24).