Opposition to animal research ranges considerably in degree. “Minimalists” tolerate animal research under certain conditions. They accept some kinds of research but wish to prohibit others depending on the probable value of the research, the amount of distress to the animal, and the type of animal. (Few people have serious qualms about hurting an insect, for example.) They favor firm regulations on research.The “abolitionists” take a more extreme position and see no room for compromise. Abolitionists maintain that all animals have the same rights as humans. They regard killing an animal as murder, whether the intention is to eat it, use its fur, or gain scientific knowledge. Keeping an animal (presumably even a pet) in a cage is, in their view, slavery. Because animals cannot give informed consent to research, abolitionists insist it is wrong to use them in any way, regardless of the circumstances. According to one opponent of animal research, “We have no moral option but to bring this research to a halt. Completely. . . . We will not be satisfied until every cage is empty” (Regan, 1986, pp. 39–40). Advocates of this position sometimes claim that most animal research is painful and that it never leads to important results. However, for a true abolitionist, neither of those points really matters. Their moral imperative is that people have no right to use animals, even if the research is useful and even if it is painless.The disagreement between abolitionists and animal researchers is a dispute between two ethical positions: “Never knowingly harm an innocent” and “Sometimes a little harm leads to a greater good.” On the one hand, permitting research has the undeniable consequence of inflicting pain or distress. On the other hand, banning the use of animals for human purposes means a great setback in medical research as well as the end of animal-to-human transplants (e.g., using pig heart valves to help people with heart diseases) (Figure 1.12).