A topic in 'Science & Ethics'
"There has never been recorded in the history of the world an instance of more extravagant trust and devotion than that told of the canine companion of a certain vivisector, which licked the hand of his master while undergoing the crime of being cut to pieces."
J. Howard Moore (1906)
'Experiments by destruction'
Scientific knowledge is generally considered a 'good' – something worth having. So, scientific enquiry would generally be seen as an ethical activity – something worthwhile. But, of course, resources have to be put into the research, and it may have other costs.
Some scientific work is basically observational – the emissions from supernovae are observed and scientists do not (cannot) either cause or influence the phenomenon. But it has long been recognised that such 'naturalistic' studies can only tell us so much – often much more can be learned by intervention (experiment).
The scientist metaphorically prods and pokes at nature, to see how 'she' responds:"men should get to grips with her".
That poking and prodding, and cutting and grinding, and freezing and heating, and so forth, may be applied to rocks and crystals, and usually no one would suggest that was cruel. But what if the object of research is a living thing: a bacterium, or a plant, or an insect, or a worm, or an octopus, or a bird or a chimpanzee, or even a human being? Are there particular ethical considerations in carrying out experiments on living things? On all, or some, living things? And if only some – which ones?
"Experiment…implies…the idea of a variation or disturbance that an investigation brings into the conditions of natural phenomena. This definition corresponds, in fact, to a large group of experiments made in physiology, which might be called experiments by destruction. This form of experimenting, which goes back to Galen, is the simplest; it should suggest itself to the minds of anatomists wishing to learn, in the living subject, the use of parts that they have isolated by dissection in the cadaver. To do this, we suppress an organ in the living subject, by a section or ablation; and from the disturbance produced in the whole organism or in a special function, we deduce the function of the missing organ. This essentially analytic, experimental method is put in practice every day in physiology.
For instance, anatomy had taught us that two principal nerves diverge in the face: the facial (seventh cranial) and the trigeminal (fifth cranial); to learn their functions, they were cut, one at a time. The result showed that section of the facial nerve brings about loss of movement, and section of the trigeminal, loss of sensation, from which it was concluded that the facial is the motor nerve of the face, and the trigeminal the sensory nerve."
Claude Bernard (1865)
Personal disclosure
I have been a vegetarian for my adult life. That is not so unusual these days, but might reflect a value system that biases my own views on the degree of acceptability of the use of animals in scientific work. Many others would approach this with quite different value positions. Teachers should perhaps bear in mind that the learners they teach likely have a range of perspectives on such issues, and not all of them will share their teacher's viewpoint.
I have obviously long been aware of the use of animals in scientific research. I recall being surprised in an undergraduate lecture in being told about the extensive amount of abattoir material needed by chemists when seeking to isolate and characterise some metabolically important natural products. Rather like Marie and Pierre Curie starting with industrial volumes of pitchblende in their work to isolate radioactive elements, tonnes of animal organs were sometimes needed to isolate a steroid hormone, with the techniques available at the time. In this example, animals were not harmed for research, but killed for commercial reasons (for food, perhaps other manufacturing processes such as glue production), and scientists made use of residual material.
"In 1931 Adolf Butenandt, then at the University of Göttingen, isolated the androgenic steroid androsterone (androstan-3𝛼-ol-17-one) from 15,000 L of urine provided by young policemen from Berlin and which were processed by Schering to obtain 15 mg of this substance…. Ernst Laqueur (1866-1947) and his group at the University of Amsterdam and at Organon were specialised in extracting hormones from animal glands. From 100 kg of bull testes they extracted and isolated 10 mg of another androgen, 17𝛽-hydroxy-4-androstene-3one, which they found to be more active than androsterone in biological tests in 1935. They baptised this hormone 'testosterone'."
Nieschlag & Nieschlag, 2019
I also remember reading-probably half a life ago, now-Steven Rose's book 'The Making of Memory' which described how he went about his scientific work investigating the molecular basis of memory.It is a fascinating book, but I was struck by the dispassionate and factual way he reported killing chicks (baby birds) to do his experiments,
"…I ask you simply to come with me through a day in the life of the lab as I go through the routine tasks of experimentation, training chicks, dissecting their brains, measuring their biochemical constituents in quantities thousandths of a milligram, and trying to extract meaning from the table of figures that these measurements produce…a small factory, with its production line and division of labour (I do the training and remove the brains…)…This killing business though. It is not easy or pleasant to reduce a bundle of yellow fluff to brain and body. "
Rose, 1992
Not easy, or pleasant…but routine. Rose was aware of the ethical issues involved, and how some people would consider his work evil, but he judged the knowledge obtained (by us) from his work justified the cost (to the chicks).
Much of the scientific discourse and legal framework relating to the use of animals in scientific work concerns the extent to which the animals suffer from pain and stress because of being held in captivity and subjected to procedures. If an animal does not experience any pain, stress or discomfort, and is 'sacrificed' (killed) humanely at the end of the experiment, is there still an ethical issue regarding their use in the experiment?
If the animal is bred especially for research, so that even a short laboratory life is some time being alive that would not have been experienced without the scientific work, is there still an ethical issue in killing the animal for science? Is such a short life, a 'good life' for the animal?
What range of views might there be among students in a single school class or university lecture?
There is an argument here parallel to that made about livestock. Many animals used in food production are bred especially for that purpose: if they have some months of life and are well-treated, and killed humanely, surely that is a bonus for them? There has, for example, been research undertaken into abattoir design to try to reduce stress up to the moment of killing. Someone accepting that view (and presumably meat-eaters at least tacitly accept this unless they are extreme hypocrites?) might feel the ethical issue is not in the killing, but in animal welfare while alive: so (simplistically) free-range is ethical but factory farming not.
Animals in scientific work
Historical attitudes to the dissection of living animals
There is a strong argument that understanding the structure and functioning of living organisms requires investigations of the living organism rather than postmortem examination of a corpse. For much of human history (and that is mostly before the availability of modern analgesics and anaesthetics), vivisection was therefore widely considered necessary and acceptable, at least of animals…and sometimes of certain human beings,
"Experiments on animals are described in literature dating from as early as 500 BC, and techniques for dissecting live animals were greatly improved by the ancient physician Galen of Pergamon (c.130-201). While there appears to have been little animal experimentation during the Middle Ages, Renaissance anatomists and physiologists of the sixteenth century both repeated and extended Galen's original experiments and devised new ones. This work led to important new discoveries, including that of 'lacteals' in the gut of a living dog (1627), which led in turn to an understanding of the lymphatic absorption of food, and the discovery of the circulation of the blood (published by William Harvey in 1628). In the sixteenth and early seventeenth centuries, few experimenters saw any religious or moral objections to the dissection of living animals…
The importance of using living animals in such research (until about 1850 without the benefit of anaesthesia) is that this could provide information not available from experiments on human or animal bodies, owing to the changes which take place after death. The use of animals to test toxic substances (began as early as the second century BC …), and in pharmacological research, has also provided information from which human and animal health have benefited. For much if history, indeed, the only alternative to envisaged to the use of animals for these purposes would have been the use of human beings; and from time to time until the eighteenth century, it was advocated that criminals in particular should be the subjects of vivisection or toxicological tests…"
Working Party of the Institute of Medical Ethics, 1991
Some of the 'heroes' of the scientific revolution (e.g., Harvey, Hooke, Boyle, Wren), were involved in animal experimentation at a time before anesthetics or ethics committees:
"Harvey found that the action of the heart could be most easily studied through experiments on small animals or [sic] fishes, as for instance observing the effect of tying ligatures about the great vessels, in suffusing or draining the chambers of the heart.
…From the members of the Academia del Cimento through Robert Boyle to the eighteenth century a series of investigators studied the effect of placing small animals in vacuo, in confined volumes of air, or of various 'elastic fluids' (gases)
…Robert Hooke showed (1667) that a dog could be kept alive by blowing into its lungs with a bellows, even with the ribs and diaphragm removed, from which he concluded that the animal 'was ready to die, if either he was left unsupplied, or his lungs only kept full with the same air; and thence conceived, that the true use of respiration was to discharge the fumes of the blood'.
…Christopher Wren (1632-1723), when an Oxford student, made experiments on the injections of fluids into the veins of animals, by which, according to Sprat, they were 'immediately purg'd, vomited, intoxicated, kill'd, or reviv'd according to the quality of the Liquor injected'."
Hall, 1954
Experimental studies of disease and pathology
As well as studying normal functioning of organisms, researchers may wish to study disease conditions, to better understand disease progression and to test out treatments. Veterinary researchers may be interested in disease in (non-human) animals; but animals are also widely used as 'models' for what might happen in diseases of humans.
That is, if it not acceptable to use humans in the research, then another species can stand in as a model of the human. Obviously, this implies that there is a judgment that the non-human animal is enough like a human to act as a good model. That is, for an animal to be a useful experimental subject to allow us to to learn about human physiology or pathology, the animal must be very like us. Indeed,
"…if we ever accepted that the liberty, good and lives of human subject could be sacrificed for medical and scientific goals in the way the liberty, good and lives of animals are sacrificed, we would find it hard to justify continuing using mere models for human biological processes when we could get at the real thing without the troubling ethical constrains operating at present."
Working Party of the Institute of Medical Ethics, 1991
Naturalistic studies would observe disease progression in animals that become diseased naturally. But this is not usually a viable approach to biomedical research both because of the difficulty of sourcing diseased animals and the lack of information about and control over their becoming ill. (Indeed, studies that only observe disease processes in humans and make no interventions would usually be seen as very questionable: for an extreme case, read about the 'bad blood' Tuskagee syphilis study.)
It is common practice, then, for diseases or injuries to be deliberately inflicted on animals to produce the material to study. The Working Party of the Institute of Medical Ethics offered some examples in their 1991 Report:
- the induction of diabetes mellitus in dogs by the drug Streptozotocin to study the development and prevention of cardiovascular complications;
- the study of leprosy in the armadillo;
- the investigation of ways of improving healing in experimental burns;
- cancer studies, involving the induction and maintenance of tumours in animals;
- the study of the epidemiology of experimental nematode worm infections in sheep.
Concerning the first example, dogs had originally been made diabetic surgically, although this effect was a chance discovery,
"In 1889 in Strasbourg, German, while studying the function of the pancreas in digestion, Joseph von Mering and Oscar Minkowski removed the pancreas from a dog. One day thereafter a laboratory assistant called their attention to a swarm of flies around the urine from this dog. Curious about why the flies were attracted to the urine, they analysed it and found it was loaded with sugar….Von Mering and Minowski subsequently proved that the pancreas produced a secretion that controls the use of sugar, and that lack of this secretion causes defects in sugar metabolism that are exhibited as symptoms of diabetes….Frederick G. Benting, a young Canadian medical doctor , and Charles H. Best, a medical student…extracted the secretion from the pancreases of dogs. When they injected the extracts into dogs rendered diabetic by removal of their pancreases, the blood sugar levels of these dogs returned to normal or below and the urine became sugar-free. The general condition of the dogs also improved."
Roberts, 1989
Testing medicines
Animals have been used in testing compounds that may act as medicines,
"In [a] German laboratory, Paul Ehrlich jabs mice, rabbits and guinea pigs with injections of strange chemical compounds which he keeps changing and discarding by the dozens. He is searching for a differential poison one which is more poisonous to the microorganism than to its host. Then one glorious morning, after six hundred and five trials, his synthetic drug-dihydroxy diamino arseno benzene dihydrochloride was its chemical name-kills the corkscrew trypanosomes, the deadly microbes that caused syphilis."
Jaffe, 1934
Animals as living factories
Animals may also be used as sources of materials that are used in research, or as hosts to act as sources of micro-organisms.
For example, monkeys were once used as the source of tissue used to prepare certain vaccines,
"…when polio vaccine was first developed, the virus was grown in cells freshly removed from the kidneys of monkeys; and in order to extract their kidneys, up to half a million monkey were killed for this purpose in a single year. At that time, it might have been argued, this was necessary in order to prevent a common, often paralysing, disease which had long proved unnameable to research. It was necessary also, because earlier attempts to find a vaccine had proceeded to human trials prematurely in some cases with fatal results…Later, however, when it became possible to grow the virus in human cells in continuous culture, the use of monkeys could not longer be defended as necessary, despite usage in some remaining countries."
Working Party of the Institute of Medical Ethics, 1991
That in this case the substituted human cell cultures were derived from tissue obtained from a human abortion (Wadman, 2017) raised other ethical issues for many people who saw abortion as inherently wrong. *
Forensic science
Animals have been used in forensic science – that is, in support of the processes of coroners' and criminal courts; as in this historical example:
"Many laboratory animals died horrible deaths for the sake of the trial, but strychnine was a relatively new poison. In the past, Taylor had been able to examine suicides who had taken arsenic, prussic acid or laudanum, and he could study the effect in hospital. Having never seen strychnine in a human being, he could only experiment on animals and imagine how those effects would scale up. In his writing on the Tawell trial, it was clear that Taylor was dubious about vivisection."
Barrell, 2017
So, much of the focus on the use of animals in scientific work is that they should not suffer any more pain or distress than is deeded necessary. Killing, as long as it is humane, is generally seen as less of an issue. Indeed, often humane killing is seen as the solution in responding to the animal's care:
For example, surgical procedures have been carried out on animals for various reasons where the procedure would lead to considerable pain for the animal. It may be suggested that if the experimental outcomes can be obtained without the animal being conscious (sometimes the case) then the animal should be operated on under aneasthetic, and then kept 'under' till the results are recorded, when the animal is killed.
One of the principles widely applied today is that an animal that has been subject to one very painful procedure should not be be subject to any subsequent procedures. So, rather than allow the animal to recover, and then be subject to more experimentation, it is considered more ethical to humanely kill the animal, and then use a new animal for the next procedure. Are there arguments for and against this ethical judgement?
Toxicity testing
As another example, a traditional measure of toxicity (once very widely used) is the LD50 test. That stands for lethal dose 50(%) and is a measure of the dose of some poison that leads to 50% fatality. (So, if the LD50 was 1µg/kg, and 100 'typical' people were poisoned with that dose (1µg per kg body weight), we would expect 5o of the people to recover and 50 to die.) For example, the LD50 of Novichok agents of the kind used by Russian state agents in the bungled assassination attempt in Salisbury (in 2018) is said to be approximately 0.22 µg/kg (Chai et al, 2018), that is about a fifth of a thousandth millionth of the mass of the victim.
Of course the LD50 is not determined by poisoning people, but rather non-human animals who are used as models (stand ins) for people. One way suggested to increase animal welfare was to not wait for the poisoned animals to die from the toxic effects, but to make a judgment when an animal was so ill it was surely to die, and then to kill it humanely rather than allow it to continue to suffer.
It might seem a little academic to find the lethal dose of a poison, as surely we should just avoid exposure to all poisons. However, when new substances are produced, or novel substances included in formulations (for dyes, pharmaceuticals, cosmetics, cleaning agents, food additives, etc.) it cannot simply be assumed they are not poisons. So toxicity testing is used to protect consumers and the wider environment from substances that could be harmful.
If taking an analgesic such a paracetamol, a user is advised to limit consumption both in terms of both the minimal period between doses and the maximum number of doses each day: such advice depends on good information of what is a safe level of use (and so on evidence of what is not a safe level of use!)
There are also many substances which are considered harmless unless ingested in high dose, where it is important to set regulations about allowed levels allowed in products. In the past commercial interests have been allowed to outweigh safety considerations – an obvious example being the use of a known poison, tetraethyllead as an additive to petrol to prevent engine 'knocking'. The lead compound was then emitted into the atmosphere in the engine exhaust. It is suggested that worldwide this caused more than a million premature deaths a year. Lead compounds, again, were used in cosmetics, as well as in paint used on (among other things) children's toys, and in pipes used for drinking waterv supply.
There are also substances which have been traditionally used, but which would not be allowed on the market if new. The tobacco industry for many years opposed restrictions on smoking (despite having evidence of the damage being caused – as long as your customers usually take decades to die from your product you can still make a healthy {sic} profit). Alcohol, while tolerated by many people in low doses, contributes to the ill health and early death of vast numbers of people: and it seems very unlikely alcoholic beverages would be allowed onto the market if this was a new product today.
Regulation
At one time there was very little in the way of formal legal framework to regulate how animals are used in scientific work. This is no longer true. (Of course this varies somewhat from jurisdiction to jurisdiction.) There are now extensive legal frameworks that restrict what can be done, and experiments and other procedures may require special licenses only awarded after subject to careful scrutiny. There has been a major initiative to limit animal experimentation to only situations which it is felt the information to be gained is important, to do whatever is possible to minimise animal suffering, to use as few animals as will lead to valid outcomes, and where possible to use what are considered less sentient creatures.
Crab blood donors
As one example, live rabbits were commonly used in pyrogenicity testing. Because of the way they are manufactured, some pharmaceutical products might include traces of bacterial exotoxins which could lead to users reacting with fever. So, rabbits would be injected with the product to see if they became feverish. This procedure has been replaced by an in vitro test using extracts from the blood of horseshoe crabs. Blood is harvested from the crabs at a level that can be tolerated without likely ill effects, before they are returned to the sea. So this does not completely eliminate the use of animals, but in the updated procedure a less salient species is subjected to a procedure less likely to cause harm.
It is generally considered that vertebrates, because of their central nervous system, are likely to experience pain, where this is less likely in most invertebrate species. (Some cephelapods may be exceptions – octopus and similar species have highly developed nervous systems, even if unlike ours.) Unfortunately, for many scientific enquiries, the animals are used as model systems to stand for humans: and so often vertebrates, sometimes, mammals, and sometimes even primates, are considered necessary to give useful results.
Large numbers of animals are still used in procedures, but only a fraction of those once employed. Increasingly alternative techniques are being developed to replace the use of live animals. The conditions in which animals (well, certainly vertebrate animals) are reared (or collected from the wild, something generally discouraged in most cases) and housed and treated are subject to strict regulations.
Overcoming anachronistic ideas
Most people beleive there is a major distinction between humans and non-humans. Even people who oppose poor treatment of animals may take the view that a human life is always worth more than a non-human life.
Would you agree that a human life is inherently more valuable than that of, say, a chimpanzee? If so, is it worth more than two chimpanzees? Is it worth more than 10 chimpanzees? A thousand? Would one human life be more valuable than all chimpanzees – that is, if you could save a human life, but only by killing off all chimpanzees so they went extinct, would that be a worthwhile deal?
How could you possibly quantify such judgements? (And if you cannot – how do you know one human life is more valuable than one chimpanzee life?)
What range of views might there be among students in a single school class or university lecture?
Aristotle believed that all living things have a soul. (Today we think of this as bring something supernatural, but Aristotle probably was thinking more along the lines of a sufficiently complex system to have special emergent properties!) Indeed animals (he thought) have two souls – they share with plants the kind of soul that enables them to feed and grow and reproduce, but they also have an additional soul that allows them to sense their environment and move around in it. Humans, and only humans, had a third soul that allowed rational thought. Only humans could become philosophers as only humans could engage in this kind of thinking.
So there was a stark divide between humans and 'the animals'.
DesCartes, about two millennia later, had an even more divisive scheme, in which humans were the only creatures that had minds and conscious experience – 'the animals' were more like automata. What looked like pain or distress was just a programmed reaction and the animal knew nothing abut it.
Clearly someone seeing animals as just very complex mechanisms, robots in effect, with no sentience might have little compunction about mistreating them. Not everyone shared this perspective (Methodist founder John Wesley, around about a century later, thought pets would be restored to life in heaven), but the distinction between man and the animals was seen as an absolute one.
The descent of man
Such an idea was easy to maintain if one believed that all species were quite distinct, and that there had been special (i.e., distinct, separate) creation of different types of beings. Such traditional ideas became scientifically non-feasible with gradual confirmation of the notion of natural selection of Charles Darwin and Alfred Russel Wallace. All life on earth is related, and species are not fixed. What separates man from his nearest relatives (the great apes) was not something absolute, but the passage of a great deal of time and many generations. People certainly did not evolve from monkeys, but both man and monkey did evolve from a common ancestor, just as, further back, man and fish had a common ancestor, and further back still, man and earthworms had a common ancestor.
No one is likely to confuse a man for a mouse today, but going back in time we would eventually reach ancestors we no longer saw as Homo sapiens; ancestors we no longer saw as human; ancestors we no longer saw as mammals; ancestors we no longer saw as vertebrates…And these 'divisions' would be more like blends than breaks – more like the transition from day into night than the shift from 2025 to 2026.
A key point is that, ever since Darwin, we have not been able to consider man and the animals – only man and other animals. If we can feel pain and be stressed, then those other animals with very similar physiology presumably also do so. If other animals have hearts that do what our hearts do, livers that do what our livers do, lungs that do what our lungs do…then presumably their central nervous systems do much as ours – including the pain receptors.
Non-humans are not just like us – but the differences are not absolute, rather matters of degree: and so if we owe moral responsibilities to fellow humans, surely we owe some (if not the same) moral obligations to other living forms?
To what extent do you think that (some? all?) animals should have some inherent rights? What are the ethical responsibilities that humans have towards non-human animals that are aware of their environment and capable of experiencing distress and pain? What scientific (that is, biological) justification is there for having protections for fellow humans that are not extended to non-human creatures?
What range of views might there be among students in a single school class or university lecture?
* You may also heard of Henrietta Lacks. She was a cancer patient who was the source of a very important cell line, HeLa. Cells taken from her tumour in a biopsy (for diagnostic purposes) during her treatment were later used to establish a cell line for research that proved invaluable to medical scientists. ,
"NIH analyzed and evaluated the scientific literature involving HeLa cells and found over 110,000 publications that cited the use of HeLa cells between 1953 to 2018. "
National Institute of Health (2022)
This case has become infamous as no consent was sought – although that was common practice at the time: scientists would make use of material obtained from treatments and it was not seen as necessary to ask the human 'source' – or even necessarily inform them. Because Lacks' tumour gave rise to a cell line that could be maintained and cultured extensively, the 'product' had considerable commercial value, but in the thinking of the time the material belonged to the scientist of laboratory rather than the person it was taken from.
The bipopsy was carried out in 1951, and HeLa cells deriving from that procedure are still used in research today. Had she been asked, Ms Lacks may well have been happy for material from biopsy to be used in biomedical research – but as she was not asked, we will never know.
Work cited
- Barrell, Helen (2017) Fatal Evidence. Professor Alfred Swaine Taylor & the dawn of forensic science. Pen & Sword.
- Bernard, Claude (1865) An introduction to the Study of Experimental Medicine (Transl. Henry Copley Greene, 1927). Dover Publications.
- Chai, Peter R., Hayes, Bryan D., Ericksond, Timothy B. & Boyer, Edward W. (2018) Novichok agents: a historical, current, and toxicological perspective, Toxicology Communications, 2(1): 45-48. doi:10.1080/24734306.2018.1475151.
- Hall, A. R. (1954) The Scientific Revolution 1500-1800. The formation of the modern scientific attitude. Longmans, Green & Co.
- Jaffe, Bernard (1934) Crucibles. The Lives and Achievements of the Great Chemists. Jarrolds Publishers.
- Moore, J. Howard (1906) The Universal Kinship (Ed.: Charles Magel, 1992) Centaur Press.
- Nieschlag, Eberhard & Nieschlag, Susan (2019) The history of discovery, synthesis and development of testosterone for clinical use, European Journal of Endocrinology, Volume 180, Issue 6, Jun 2019, pp.R201-R212, https://doi.org/10.1530/EJE-19-0071
- Roberts, Royston M. (1989) Serendipity. Accidental discoveries in science. John Wiley and Sons
- Rose, Steven (1992). The Making of Memory. From molecules to mind. Bantam Press.
- Wadman, Meredith (2017) The Vaccine Race. Science, politics, and the human costs of defeating disease. Viking.
- Working Party of the Institute of Medical Ethics (1991) Lives in the Balance. The ethics of using animals in biomedical research (Jane A. Smith & Kenneth M. Boyd, Eds.) Oxford University Press.
