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Animal Research


Non-human animals are used in medical and other scientific research at academic institutions, hospitals, and in industries such pharmaceuticals and cosmetics.  Scientific research on animals helps develop antibiotics and other medications, as well as immunizations and surgical procedures.  Animals are used in the testing of consumer products such as perfumes and shampoos.  Animals are also used to educate students in biology, medicine, and related fields.  We will call all such efforts “animal research.” 

Rats and mice are the main animals used, but also used are birds, reptiles, amphibians, fish, and other mammals.  In the course of animal research many animals suffer discomfort, fear, and pain, and some animals die.  Of course, many animals in the wild suffer and die also, hence the famous expression:

“nature red in tooth and claw.”

Animal research is morally controversial.  Many scientists just assume that it is morally permissible, but animal rights advocates claim that it is not.

Arguments For Animal Research

Humans use animals for their purposes and do so for the most part without thinking the practice needs moral justification.  People have used and continue to use animals for transportation, farming, recreation, companionship, sport, and food.

Likewise the use of animals in research has occurred largely without researchers thinking they needed to morally justify this practice.  But if a justification is thought to be needed, the main one given by supporters is that such research brings great benefit to humans, enough benefit to outweigh any possible animal suffering or sacrifice involved.

Furthermore, those who support animal research usually hold that most scientific results obtained through animal research are not available in any other way or that the use of animals in research is more effective than other possible methods that might be used to obtain this scientific knowledge.

Here is a sketch of some important claims assumed or given in support of animal research:

  1. It is morally permissible for humans to use animals, that is, to raise them and keep them for our purposes, to do things with them and to them, and to make things out of them.  For example, we may eat them, use them for clothing, use them for farm work, put them in service as guard animals and guide animals, use them as pets, do research on them, etc.
  2. Animals have no right to life, no right to live their own lives, and no right not to be used for human purposes.
  3. Any suffering endured by animals in research contexts is justified by the benefits to humans from such research.
  4. Computer modeling and other study methods not involving animals would not be able to fully replace the use of animals in research because we would not gain as much knowledge by these other techniques.


In recent years there has been some discussion among ethicists about animal rights and how we should treat animals, and as a result we can add a few modifications or qualifications that those who support animal research usually now will concede:

  1. Animals may have no right to life, but they deserve some sort of moral consideration that disallows some kinds of treatment of animals.  For example, it would be wrong to torture animals for fun.  If possible, they should be treated humanely and not made to suffer unnecessarily.
  2. Controls should be in place to protect research animals from unnecessary harm (pain and suffering).


This modern qualified version of support for animal research grants animals some sort of moral consideration or moral status; some animal research advocates may go so far as to allow that animals have some limited moral rights.  Most people grant that it would be wrong to make or allow an animal to suffer or torture an animal just to provide us with amusement or entertainment.  This could be stated in terms of human moral obligations – we have a moral obligation not to torture animals – or in terms of animal rights – animals have the right not to be tortured.  Also, there have been concerns during the last few decades that animals in zoos should be provided with better, more realistic habitats so that they have more of a life.  None of this is taken to preclude scientific research, though it might complicate it, but it is now commonly recognized that steps should be taken by researchers, sometimes at significant cost to the research project, to treat research animals humanely and limit any suffering.

An example of a defender of a more or less traditional view supporting animal research is Carl Cohen.  Cohen thinks that the tremendous benefit to humans from animal research outweighs any possible suffering on their part.  Efforts are and should be made to prevent mistreatment of research animals.  Cohen does not believe it makes sense to speak in terms of animals having moral rights, even limited rights not to be tortured, though Cohen would think it is wrong to torture animals.  Cohen’s view is that to have moral rights, a creature must have the capacity to have their own moral duties or engage in moral reflection or deliberation.  While humans can do this, non-human animals cannot.  Research animals therefore are not part of the moral community and can have no moral rights.

Animal Rights Advocacy

A position against traditional and more modern views supporting animal research is represented by diverse opponents we will group together as “animal rights advocates.”  Animal rights advocates often concede animal research has benefitted humans, though some advocates believe the benefit has been overblown and could have been provided in other ways.  But on their view no benefit from animal research could make such research morally permissible.

A number of distinct views are held by animal rights advocates:

  1. Animals are not on this earth to be used for human purposes.  They have their own lives.
  2. Animals have moral rights which are violated by using them for research or killing them for food or clothing.
  3. Animals used in research are often mistreated, despite the presence of controls meant to prevent this.
  4. Any human benefits through animal research are outweighed by the suffering of those animals.
  5. Benefits from animal research are greatly exaggerated: many research results are insignificant or useless (because animals are not like humans, results are often inconclusive) or could have been obtained in other ways.


Utilitarianism and Animals

Probably the most important theoretical perspectives from animal rights advocates come from Peter Singer and Tom Regan.

One tradition in ethics is that when faced with several alternative courses of action, one should choose the course of action that will result in the greatest good or happiness for the greatest number.  Versions of this tradition are called “utilitarianism.” 

One interpretation of utilitarianism interprets the “greatest number” to mean the greatest number of human beings.  A different view of “greatest number,” one represented by Singer, claims we should take into account not just human beings but any creature who can have conscious experience, feel happiness, and experience pain and suffering.  In judging the rightness or wrongness of a practice, everyone’s interests, happiness, pain, and suffering, including those of research animals, need to be taken into account. 

What of the claim that research benefits to humans outweigh any possible suffering of research animals?  According to Singer, the suffering of research animals is on par with that of humans, so for such research to be justified by future benefits, those future benefits would have to be able to justify it if the research were carried out on human infants.  Only if the pain, suffering, and other harm to human infant research subjects were considered justified by future benefits would it be justified to use animals instead of infants.  If one objects that human infants have greater potential than animals, and so should count for more or count in a more significant way, Singer suggests we consider whether we would do such research on brain-damaged infants who have no more intellectual potential than animals.

Singer and those who agree with him are not advocating we test new drugs on normal infants or brain-damaged infants instead of on non-human animals.  They merely want to make us see that we have no real grounds to consider only the interests of humans and treat animal interests, happiness, and suffering as if they don’t really matter.  Singer considers the view that human lives and interests are preferable to animal lives and interests to be a prejudice, a prejudice of “speciesism” that he considers analogous to racism.  Singer thinks we should consider speciesism wrong just as we consider racism wrong.

Singer at times speaks of animals as having rights.  His view that animals have interests and can experience happiness, pain, and suffering is consistent with them having moral rights, but note that, traditionally, utilitarians think of moral rights as akin to “useful fictions” rather than ultimate “metaphysical” possessions of conscious beings.

Regan’s Defense of Animal Rights

For Tom Regan, to say human beings have moral rights to life and liberty means others are not free to harm individuals or ordinarily interfere with their free choices.  Why do humans have moral rights to life and liberty?  Regan thinks it is because humans are subjects whose lives matter to them; a human being is (in his terms) a “subject-of-a-life.” 

But then, Regan notes, nonhuman animals are likewise subjects-of-a-life.  Nonhuman animals are aware of what happens to them and what happens to them matters to them.  Their lives can go “better or worse for them.”  They are subjects, not just objects, and one can say in the case of a nonhuman animal there is “somebody there.”   So, according to Regan, like humans, nonhuman animals have moral rights to life and liberty.

Regan holds that the use of animals in research violates their moral rights.  Subjecting an animal to suffering and death as part of scientific research violates the animal’s rights to life and to live that life in a way meaningful to the animal.  Their rights “trump” any purported justification of animal research as benefitting humans.

Regan is suspicious of the common claim that human benefits justify animal suffering anyway.  No one has ever worked out any kind of intelligible methodology that would enable one to compare benefits to one species with the harm to another species so as to show the former outweighed the latter.  The usual assumption seems to be that the suffering of an animal counts for less than the suffering of a human, but Regan questions this.

Issues in the Dispute

The controversy between the views supporting animal research and the view of animal rights advocates involves disputes about both factual (empirical) and moral issues.  Disputed factual issues include:

  • whether scientific results obtained through animal research are significant
  • whether the same or similar results could have been obtained through other means, and
  • whether effective controls are in place to protect research animals from mistreatment.

Moral issues include:

  • the moral status and moral rights, if any, possessed by nonhuman animals, and
  • whether research animal suffering is justified in light of the benefits of such research to humans. 

This latter issue has empirical aspects too, because it involves answering factual questions of how much suffering occurs to research animals and how much humans really benefit from animal research.

A thorough discussion of all these issues is too much for this introduction, but the following comments on some of the issues may help you decide on your position on the morality of animal research. 

Factual issues:  It seems beyond argument that the use of animals in medical research has benefitted humans in many ways, for example in developing immunizations for measles and polio, in the development of antibiotics, and in the development of surgical techniques such as organ transplants and joint replacements.  Developed through animal research, vaccines for rabies and distemper have benefitted family pets as well.  It’s hard to imagine all this being done by computer modeling, and in fact much of this was done before computers were commonly available.  But it is worth considering whether, going forward, for some kinds of research more use of testing by means other than on animals might be just as effective.

In the context of research in the United States, controls are in place or being put into place to try to minimize animal suffering.  Whether or not these controls are fully effective and optimal is open to debate.  In this regard research seems to have come a long way from practices of decades ago, but we may need to police current policies better or put in place more stringent ones.

Moral issues:  The moral issue of whether human benefit justifies animal suffering and sacrifice itself has both moral and factual aspects:

  • what constitutes human benefit (moral) and how to quantify that (factual)
  • how to value the life of a research animal (moral)
  • what constitutes animal suffering and sacrifice (moral) and how to quantify that (factual), and
  • how to compare benefits and sacrifices across species (moral and factual). 

Regan is correct that the math of any “justification equation” is rarely even discussed, much less spelled out in any noncontroversial fashion.  In other words, there is no clear way to precisely quantify the suffering of research animals and compare this amount to a calculated quantity of human benefit to see if one outweighs the other.

In another respect, some people might seem confused about the issue of justification itself, sometimes assuming no justification is needed and yet at other times thinking animal research is justified by human benefit, as if justification were needed.

Obviously a key moral issue in the dispute is the precise moral status of nonhuman animals.  The moral status of something is whether the thing is a moral agent and/or a moral patient, whether it has moral rights, and if not whether it deserves some other sort of moral consideration.  For most people the sense of moral patiency possessed by such animals is very limited and gives them limited rights.  They may have the right not to be harmed for fun.  (But not everyone who believes this would be comfortable talking of such animals as possessing rights.  They might be more comfortable saying such animals deserve some moral consideration.)

Animal rights advocates of course would be comfortable with the view that animals are full-blown moral patients; Regan claims they have a right to life.  Animal right advocates just disagree here with Cohen that animals are not part of the moral community.  They are not moral agents, but they are moral patients.

Why do some things have a different moral status than do other things?  It might be that we implicitly base the moral status of something on some physical or metaphysical feature of that thing.  So for instance human beings are thought to have moral rights to life and liberty while trees do not because humans are conscious, rational, can express wishes and desires, have their lives matter to them, have an interest in their futures, etc. (physical features in the broad sense -  including mental), while the same cannot be said of trees.  Or human persons have immaterial souls (metaphysical features) while trees do not.  Or animals are considered to be subjects (a metaphysical category), just as humans are.

Regan thinks the moral status of a thing depends on it being the subject of a life, having a future that matters to it.  Regan’s type of view tends to see things as black or white.  If it is the subject of a life, it has the moral right to life, otherwise not.

To be consistent we should grant the same moral status to creatures that are relevantly similar physically or metaphysically, depending on what it is we think that grounds moral status.  Aliens from another planet who acted like human beings in certain essential ways might be given a similar moral status, though they were not human.  However, one could argue that moral status comes in degrees and is not absolute in the way Regan thinks.

Another consideration is whether the moral status of a being could be overridden by other factors.  So, for example, one might claim that nonhuman animals deserve a certain kind of moral treatment but in the case of crucially important research trying to save human lives that status can be overridden.

Carl Cohen and Tom Regan, The Animal Rights Debate
Peter Singer, Animal Liberation
Tom Regan, Empty Cages

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