Changing the Subject


This case describes in detail an experiment on an animal meant to stimulate discussion about the ethical issues that arise in animal research.


Ken Shu's graduate research involves the use of animals to explore the workings of the central nervous system. In order to perform his experiments, Ken needs a fully functioning animal with a working nervous system -- in other words, the animal must be conscious. The experimental procedure begins with the administration of anesthetic, not for the animals' benefit, but for experimental convenience: It is much easier to handle the animals initially if they are rendered temporarily unconscious.

There is no cheaper or more effective anesthetic than carbon dioxide, which works simply by cutting off the animal's oxygen supply. The animals struggle violently when Ken places them in gas chambers constructed for this purpose, until the oxygen content in their tissues drops below the level necessary to support consciousness. Gross surgery is performed at this point. Ken works quickly to restrain the animal and remove its limbs, preventing further struggle that might result in nerve damage during the finer surgery to come.

The finer surgery takes an hour and a half on the average. Although the animal need not be conscious during this period, exposure to carbon dioxide for such a long period would either kill the animal or cause irreversible brain damage, both unacceptable outcomes. Therefore, the animals are allowed to regain consciousness during the finer surgery. By the time an animal awakens, its legs are gone. Usually the animal explores the proximal stumps that remain after limb removal with its mouth. The animal tends to shake a little after exploring the wound sites, probably from shock. After the finer surgery and with its head braced, the animal, now reduced to an experimental prep, is subjected to intra-cellular penetrations of interneurons in its central nervous system in order to explore the relationship between nerve cell activity and animal behavior. The final phase of the experiment can last another eight hours if the animal survives that long. All of these procedures are performed without pain killers in a fully conscious animal.

Ken had always felt some degree of compassion for the experimental subjects. One day, he could no longer hold in the doubt he felt about the experiments, so he discussed his concern with his adviser, Dr. Carol Brown. Ken began his discussion with the often observed phenomenon of the animal searching for its missing limbs, and his fear that this behavior might indicate too high a level of self-knowledge for the types of experiments being performed in the lab. Even if this phenomenon could be discounted, Ken added, the existence of pain receptors in the animals implies a capacity for suffering.

To these concerns, Brown responded: "Do you have any idea where biological understanding would be today if it weren't for animal experimentation? These experiments may enhance our capacity to repair our nervous systems, give us new engineering approaches to information processing or even help us to design novel nervous systems. Even if these animals were self-aware, and most reputable scientists would disagree with you on that one, the ends of our experiments justify the means."

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Discussion Questions

  1. What criteria should be used to determine whether experimentation on a given animal is ethical? Some hold that the test should be that animal's capacity to suffer. In this case study, the animal in question has pain receptors and thus can presumably perceive pain. Yet the experimenter makes no attempt made to control the animal's pain. Is that ethical?
  2. If the experimenter uses anesthetic to alleviate the animal's discomfort, does that change your perspective on the ethics of the case study? If so, do you think it would be acceptable to use an anesthetized human in the experiment?
  3. Some hold that the ethical test for experimentation on a given animal is that animal's level of awareness. However, there are no objective criteria to determine an animal's level of awareness. Presumably, primates have a high level of awareness, yet experiments are carried out on other primates that would never be allowed on humans. If you think awareness should be considered when determining the types of experiments that are permissible on a given species, what are some objective guidelines that should be used to determine the animal's level of awareness?
  4. Some hold that social contract theory adequately explains animals' lack of rights; that because animals are unable to enter into a social contract with humans, we have no obligation to treat them one way or another. If individual humans are unable to represent themselves to our society, it is customary to provide them with advocates. Should animals have advocates?
  5. Should it ever be permissible to perform experiments of this nature on humans?

Used with permission of Association for Practical and Professional Ethics. Case drawn from Research Ethics: Cases and Commentaries, Volume Two, Brian Schrag, Ed., February 1998.

. . Changing the Subject. Online Ethics Center. DOI:.

The case describes an experimental procedure conducted on a particular kind of animal (a procedure that in fact is actually and routinely carried out on the animal) and raises the fundamental issue of how we justify conducting research on animals that we would never justify conducting on humans.

One might ask whether the "facts" of the case really do or can remain the same whatever animal is "plugged in." Are the facts equally appropriate, for example, whether the animal is a monkey or a cockroach? Would carbon dioxide really be the anesthetic of choice in both cases? If it is not necessary as an anesthetic in the case of the monkey, would it really be necessary to allow the monkey to regain consciousness during the experiment? Would removal of limbs (as opposed to some restraining devices) really be necessary on monkeys?

Given these sorts of considerations, one might think it is not sensible to expect to test our intuitions about ethical treatment of animals by imagining our responses if we "plugged" various animals, including humans, into a single experimental design of this sort. Nevertheless, one should not dismiss the issues raised by such a thought experiment too quickly. However one resolves the question of the universality of this particular experiment, it is certainly reasonable to assume that one could consider a complex of cases that raise the same issues.

One could imagine, for example, experiments devised by an "alien" that inflict this sort of pain and suffering on humans. One can identify experiments devised by humans (e.g., the use of rats to assess the pain experienced by humans in burn injuries)(1)  that appear to subject higher vertebrates to pain and suffering similar to that inflicted in this case. Finally, actual experimentation on invertebrates results in the behaviors and reactions described in this case (however one interprets those behaviors).

Suppose for the sake of argument that this particular experiment were to be performed on a variety of species. Would we think the moral justification for applying or not applying this same experiment would differ for different animals, including humans? If so, to what criteria would one point to justify the difference?

That our actual standards and review procedures for experimentation on humans differ from those for animals reflects the fact that most persons assume that scientific protocols involving human subjects should be assessed differently than protocols involving animals. However, there is currently no consensus in the ethics community regarding the moral criteria for determining when, if ever, experimentation on animals is justified.(2) This lack of consensus reflects some absolutely fundamental disagreements regarding the nature of humans and their relation to other animals as well as fundamental disagreements over core concepts in morality.

One can identify a spectrum of positions on this question.(3)  I will summarize the positions of four ethicists to illustrate that spectrum. Some would argue that there can be no moral justification at all for experimentation upon animals. One argument for this view starts from the position that we recognize humans have moral rights. Moral rights place limitations on what people are free to do to each other. Because humans have moral rights, we reject the notion that it was acceptable for the Nazis to perform hypothermia experiments on prisoners simply because the knowledge gained could benefit other humans. The source of our human rights, so the argument goes, is that we are sentient creatures; we have a capacity to experience pain and pleasure. But if that is true for humans, it is also true for many species of animals. Sentient nonhuman animals have the same moral rights as humans in this regard and should no more be experimented upon for the benefit of humans than we should experiment on prisoners, children or any other humans simply for the benefit of other humans. On this view, experimentation on nonhuman sentient animals is unjustified and should stop now. The interests of humans cannot outweigh the rights of rats. If there are some things we cannot learn because we cannot experiment on animals, so be it.(4)

At the other end of the spectrum is the view that there is nothing wrong with experimentation on animals. One view accepts that many animals are sentient creatures, and for that reason humans have an obligation to not to avoid gratuitously inflicting pain and suffering on them. However, there is no parallel between Nazi experimentation upon humans for the benefit of other humans and experiments on rats for the benefit of humans. Humans have moral rights; rats do not. The moral status of humans and animals is very different. That difference does not arise from particular cognitive properties of humans such as self-consciousness, rationality and the ability to communicate. Rather, the human species is unique among animal species in having a capacity for moral reasoning and discourse; only humans are capable of grasping and laying down moral laws for themselves and others. Consequently, only the human species is capable of having and being in a moral community. Moral community is a necessary condition for having moral rights. Thus we do not violate the rights of animals when we experiment upon them for the benefit of humans, and it is acceptable to do so.(5)

A third view denies that moral standing and moral rights are necessarily tied uniquely to members of the human species as specified in the previous position.(6) Rather, moral standing in creatures is tied to properties of creatures that warrant giving them the protection of morality. If a being has moral standing, it also has moral rights. Acknowledging that a being has moral standing is to recognize that it has interests that humans must take into account; that also distinguishes it from beings whose interests have less moral weight. Certain cognitive properties are frequently invoked as the criteria for assigning moral standing. Thus, it is often suggested that self-consciousness, purposive action, capacity for language, capacity to make moral judgments and rationality are properties that justify assigning moral status to a being. But it is plausible to argue that certain nonhuman animals posses some of these qualities and sometimes at a higher level than some humans (e.g., infants or demented adults). Furthermore, it is not clear why only these qualities are relevant to assigning moral standing. Why should not the capacity to feel emotion (note the recent work on the emotional life of animals) or pain be sufficient to give a creature a degree of moral standing? "The question is not, Can they reason? nor Can they talk? but, Can they suffer?"(7) The fact that animals can suffer imposes some obligation on us not to inflict pain on them and to recognize that infliction of pain is wrong no matter what the benefits. At minimum, this imposes upon humans an obligation not to exceed certain limits in the infliction of pain in other animals. (Setting acceptable levels of pain in experimentation on animals is required by law in some countries, but not the United States.(8) ) On this view, we may be justified in conducting certain animal experimentation, but we are justifiably constrained to not exceed certain levels of pain no matter what the benefits to humans and otherwise constrained by the amount and type of pain inflicted as well as the merits of the research.

A fourth view holds that how we treat humans and animals in experimentation should be determined on the basis of the value of their lives, which is, in turn, a function of the quality of their lives.(9) Thus, moral standing is not determined by an appeal to moral rights. Rather, moral standing is determined by whether a creature can be an experiential subject, capable of having a series of experiences that can make the creature's life go well or not depending on the quality of those experiences. It has a welfare that can be improved or negatively affected by what we do to it. Normal adult humans fall in this category, but so do demented patients, frogs and lion cubs. This is so whether or not we agree they all have moral rights or are all moral agents. (Mere adaptation to environment does not count as being experiential. Some creatures, - e.g., plants in general - are not experiential.) Moral standing varies with the quality of life.

The quality of a life is a function of its capacity for richness. A normal adult human with the capacity to appreciate music, literature, science has a richness and hence quality of life not approached by a puppy. Nonhuman animal life, in general, probably would not have the same value as human life because the quality of life is not as high. Nevertheless, even if an animal lacks some of the richness of the normal adult human, it still has some value, and animals are not to be simply sacrificed the way one might discard broken lab apparatus. It is important to emphasize that on this view, it is not the species to which an animal belongs that determines the value of the life; it the animal's quality of life.

Quality of life includes more than considerations of pain and suffering, although those considerations are morally relevant. On this view, pain is pain, and the species makes no difference in terms of the moral significance of the pain. There is no moral difference in the pain caused by pouring scalding water on a baby or a puppy or a lobster. (One researcher has noted that the mortality rate for human burn victims at the turn of the century was quite high. It is now less than 5 percent, and that decline is directly attributable to experimentation on animals such as rats.(10) On this view, such research would be justified.)

It also follows from this view that not all humans have the same quality of life and hence the same value or moral status. It is possible in principle that some nonhuman primate could have a quality of life higher than that of some human. One implication of this view for animal experimentation is that although in general one might justify experimentation on animals on the basis of benefits to humans, there may be instances in which the quality of life of nonhuman primates, say, is higher than that of some humans, and the experimentation should be done on those humans rather than the primates.

The actual standards and regulations guiding experimentation on animals have evolved in the United States over the past 30 years.(11)  The legal regulations are principally spelled out in the Animal Welfare Act, the Public Health Service Policy on Humane Care and Use of Laboratory Animals, and the Good Laboratory Practices of the Food and Drug Administration. In addition, there are the voluntary regulations of the American Association for the Accreditation of Laboratory Animal Care.(12) The latter are set forth in the Guide for the Care and Use of Laboratory Animals, which is an influential document worldwide.(13)  The Animal Welfare Act requires the CEO of each research facility to create an Institutional Animal Care and Use Committee (IACUC) to ensure compliance with the Act. IACUCs are now the major formal review mechanism in the United States for proposed animal experimentation. The Public Health Service also requires IACUCs for institutions with projects funded by the PHS, and those projects are expected to follow the standards of the Guide. The Guide is intended to apply to vertebrates and does not specifically address the treatment of invertebrates.(14) As a general rule, IACUCS do not concern themselves with protocols for the treatment of invertebrates.

There is considerable variation between the United States and some other countries regarding oversight and standards.(15) U.S. law does not require that IACUCs consider the ethical justification of an experiment, unlike the laws of the United Kingdom, Germany, the Netherlands and Australia. Those countries require that institutional review committees weigh the ethical cost to the animals against the human benefits derived from the research.

In several countries (not the United States), review boards are required to assess the level of pain to animals likely to be inflicted by the proposed experiment and, if the level is too high to be ethically justified, the experiment is disapproved irrespective of the scientific benefits of the experiment. Systems (scales of invasiveness or pain) to categorize the degree of animal pain in experimentation are incorporated into the national policies of Canada, The Netherlands, United Kingdom, Switzerland, Finland and Germany (but not the United States). The actual effect of such review may depend on who sits on the committees. Researchers understandably have a vested interest in advancing research and little incentive to place the welfare of animals above research. Orlans reports on a survey of licensed animal researchers in the Netherlands: When they reviewed proposed protocols that involved considerable harm to nonhuman primates, the researchers assumed the project was justified and did not question its purpose.(16)

The questions "Do animals experience pain and suffering?" and "If so, how could one tell?" are prior to the debate over the trade-off between benefit to humans and the pain inflicted on animals. Even if we allow that animals that are most like humans do experience pain and suffering, what about "lower" vertebrates and invertebrates? Much of the debate over our moral obligations in experimentation on animals and in the guidelines and standards centers on these questions.

Some argue that animals, compared to humans, do not feel pain or as much pain or at least we can never be sure they feel pain, and hence it is acceptable to subject them to experiments that would cause pain and suffering in humans. These questions are in part arguments in conceptual analysis in the philosophy of mind and not empirical questions.(17)  Even if some animals feel pain, there is still the question of the degree to which various nonhuman species experience pain. Invertebrates are often thought to be suitable replacements for vertebrates in experiments because they are thought to be insentient or at least less sentient than vertebrates. Thus, in the case under discussion, it would matter whether the experimental animal was a monkey or a cockroach.

We cannot resolve these issues here. Nor is it reasonable to suspend scientific research until the conceptual issues are resolved.(18)  Notice, however, that it would be inconsistent for researchers on the one hand to assume that rats are reasonable models for learning about human responses to pain or the effectiveness in humans of various analgesics, say in burn treatment, and yet assume that we have no idea whether or not rats experience pain.(19) At a practical level, the proposal found in the Guide for dealing with vertebrates may seem the most prudent: "In general, unless the contrary is known, it should be assumed that procedures that cause pain in humans also cause pain in animals."(20)

Even if we assume that vertebrates feel pain, the issue of pain in invertebrates is more difficult. Humans share a basic physiology with mammals, and similarities in neural organization with all vertebrates. Our physiological similarities with invertebrates are much more tenuous. Should we be more concerned than we are with the treatment of invertebrates in research? Can cephalopods (which have the largest brains of all invertebrates), experience anything like what we call pain?(21)  In the absence of clarity on this issue, perhaps the most reasonable course, as suggested by one researcher, is to follow a principle of respect. That is, when using invertebrates in research, we should maintain the highest possible standards of husbandry and care and, where questions of pain and suffering are concerned, give the animals the benefit of the doubt. That would include avoiding the use of the more complex species where possible, and anesthetizing the animals in procedures that have the potential to inflict pain.(22)

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  • (1)See for example, Patricia F. Osgood, "The Assessment of Pain in the Burned Child and Associated Studies in the Laboratory Rat," ILAR NEWS 33 (1-2, Winter/Spring 1991): 13-18.
  • (2)For an excellent recent collection of essays featuring an exchange of views by leading ethicists and scientists on the use of animals in research, see Ethics and Behavior 7 (2, 1997).
  • (3)For a brief overview of the issues, see Deni Elliott and Marilyn Brown, "Animal Experimentation and Ethics," in Deni Elliott and Judy E. Stern, eds., Research Ethics: A Reader (Hanover: University Press of New England, 1997), pp. 246-259.
  • (4)See Tom Regan, The Case For Animal Rights (Berkley: University of California Press, 1983). For his own summary of his views, see Tom Regan, "The Rights of Humans and Other Animals," in Ethics and Behavior 7 (2, 1987): 104-111.
  • (5)Here I summarize the argument of Carl Cohen, "Do Animals Have Rights?" in Ethics and Behavior 7 (2, 1997): 91-102. See also Carl Cohen, "The Case for the Use of Animals in Research," New England Journal of Medicine 315: 865-870.
  • (6)See Tom Beauchamp, "Opposing Views on Animal Experimentation: Do Animals Have Rights?" Ethics and Behavior 7 (2, 1997): 113-121.
  • (7)Jeremy Bentham, The Principles of Morals and Legislation. Chapter 17, Section 1.
  • (8)See F. Barbara Orlans, "Ethical Decision Making About Animal Experiments," Ethics and Behavior 7 (2, 1997): 123-136.
  • (9)See R. G. Frey, "Moral Community and Animal Research in Medicine," Ethics and Behavior 7 (2, 1997): 173-184.
  • (10)Osgood, "Assessment of Pain," p. 15.
  • (11)For a history of development of regulation in the United States, see Nicholas H. Steneck, "Role of the Institutional Animal Care and Use Committee in Monitoring Research," Ethics and Behavior 7 (2, 1997): 173-184.
  • (12)For a summary of the relevant U. S. rules and regulations, see B. T. Bennett, M. J. Brown and J. C. Schofield, eds., Essentials for Animal Research (Beltsville, Md.: National Agricultural Library, 1994), pp. 1-7. Reprinted in Elliott and Stern, eds., Research Ethics, pp.246-259.
  • (13)Institute of Laboratory Animal Resources, Commission on Life Sciences, National Research Council, Guide for the Care and Use of Laboratory Animals (Washington D.C.: National Academy Press, 1996).
  • (14)Ibid., p. 2.
  • (15)I draw here on Orlans, "Ethical Decision Making."
  • (16)Ibid.
  • (17)See, for example, the following exchange: Peter Harrison, "Do Animals Fell Pain?," Philosophy 66 (1991): 25-40, and Ian House, "Harrison on Animal Pain," Philosophy 66 (1991): 376-379.
  • (18)For an extended discussion on both the empirical and philosophical issues, see Beckoff et. al., "Animals in Science: Some Areas Revisited," Animal Behavior 44 (1992): 473-484.
  • (19)For a discussion of the empirical work on the relation of human to animal pain, see Fred Quimbly, "Pain in Animals and Humans: An Introduction," ILAR News 33 (1-2): 2-3; Francis J. Keefe et. al., "Behavioral Assessment of Pain in Animals and Humans," ILAR News 33 (1-2): 3-13; Osgood, "Assessment of Pain."
  • (20)Guide, p. 64.
  • (21)For a discussion of the evidence of pain in invertebrates, see Jane A. Smith, "A Question of Pain in Invertebrates," ILAR News 33 (1-2): 25-31.
  • (22)Ibid., p. 29.

Author: Brian Schrag, Association for Practical and Professional Ethics.

A poster on the door of a biologist's office reads, "You wouldn't be here to protest animal experimentation, if it weren't for animal experimentation." Whether or not that statement is true, we all enjoy the benefits of animal experimentation. The drugs we take were tested first on animals. Many medical advances that guide physicians and prolong our lives owe their discovery to the animal "models" chosen by the researchers. But is that right?

A philosopher friend of mine described a thought experiment he conducted to answer the question. Suppose you were in a room with fifty puppies. In the next room were all of the members of your family being held hostage by terrorists. You could foresee the future (important since terrorists are not to be trusted), and you knew that the terrorists would turn themselves over to the authorities and release your family unharmed, if you submitted to their demand to break the necks of all fifty puppies. He said that he would do it. He argued that this situation was analogous to animal experimentation and clarified the value of human life.

But what if the puppies were human babies? There is a strong tendency to want to preserve human life over animal life and to preserve familiar lives preferentially. But should feelings and beliefs be our ethical guides? I would like cold, hard reason to guide these sorts of decisions. In the case of the puppies, it is clear that losing one's entire family would be a greater personal loss for most people than losing fifty cute but unfamiliar dogs. I'm sure one could get over the trauma of killing the dogs with the help of family. From a personal perspective, the best decision is to kill the dogs.

That seems to be the level at which almost all moral reasoning occurs: the personal level. One usually chooses the answer first and then seeks to justify it using argument. If one steps back a little from the personal and looks at moral scenarios as an outsider, then the apparent clarity of moral problems begins to disappear. If one were not human, what would be the correct answer in the puppy problem? Is it right to kill fifty members of Species A to serve ten members of Species B?

There is a genuine lack of objective criteria for the ethical treatment of living beings. What exactly is it that makes it acceptable to perform experiments on certain animals, but not on people? Biologists have found many similarities among animals. We all have cells. Many of our main tissue types are nearly identical across family lines. There are also many differences, of course. But which of these differences are important in determining which types of experiments (if any) are acceptable if performed on a given animal? Unfortunately, animal experimentation may be necessary to provide the information that will enable us to answer these sorts of ethical questions.

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