Image: Defendant Dr Karl Brandt being sentenced to death at the War Crimes Tribunal, 19 August 1947, Nuremberg

While many of us, on occasion complain about having to get ethical approval, it is important to be aware of the history behind these obligations. This is especially true with the recent resurgence of the far-right and Neo-Nazis leading to a growing sense of darkness in the world. It is thus apt to remember that 2017 marks the 70th anniversary of the Nuremberg Code that emerged from the Doctors’ Trial following World War II.  It was this code that forms the basis of many of the ethical standards governing research today.

Of the many horrors associated with the Holocaust, Nazi Doctors performing experiments on political prisoners, Jews and other camp inmates was one of the most callous. The details make for horrifying reading. The German air ministry, for example, wanted to know if it was possible to protect aircrew from hypothermia. To learn about this, they immersed naked prisoners in iced water until they became unconscious, and many died as a result. Other experiments conducted by Nazi scientists involved: intentional severe injury and infection; exposure to extremes of temperature and pressure; unneeded transplants; and exposure to hazardous chemicals and biological agents. The doctors who conducted these experiments never sought consent and many of those subjected to their experiments suffered painful lingering deaths.

In December 1946, the allies convened a military tribunal to judge the scientists that had run these experiments. The so-called Doctors’ Trial (formally known as United States of America vs Karl Brandt et al. 1946-47) involved 23 defendants, the majority of whom were doctors. The chief prosecutor, Telford Taylor, pointed out in his opening statement that this was “no mere murder trial” because the defendants had sworn to “do no harm” and to abide by the Hippocratic Oath. He went on to say that the world needed to know:

“with conspicuous clarity” the ideas and motives that moved these doctors “to treat their fellow human beings as less than beasts,” and that “brought about such savageries” so that they could be “cut out and exposed before they become a spreading cancer in the breast of humanity.”

One of the problems that prosecutors faced was a lack of formal codes governing research. Ironically there were ‘Guidelines for Human Experimentation’ passed by the Weimar Government in 1931.  These did offer some protection for people taking part in research.  Yet the Enabling Act of 1933, marking the beginning of the Nazi era, meant that such laws held no legal force.

The lack of formal international codes does not imply that research before the war was unethical. Indeed, throughout the 19th century, there was debate about what was acceptable research. Thus there was an informal agreement on what was acceptable, but there were no international codes of research practice.

During the Doctors’ Trial, the defence took two forms. First, that defendants were only ‘following orders’. Second, the alleged activities were a normal part of scientific research. It was true that scientists conducted similar experiments in America, Britain and Germany before the war. Vulnerable groups and prisoners were subjected to invasive experiments without any meaningful consent. The defence also argued that the defendants had broken no formal codes covering research conduct and ethics.

Despite these defences, of the 23 defendants, 16 were found guilty, and the rest acquitted. The court ruled that scientists cannot stray from their ethical responsibilities, even if ordered to do so.

The arguments made by the defence, about the lack of codes of practice governing research, troubled some of the judges. As a result, they worked on a six-point code defining acceptable ethical standards for future research. These six points were later expanded to ten points and became known as the ‘Nuremberg Code’. This code was the first attempt to set international standards for research involving humans.



  1. The voluntary consent of the human subject is absolutely essential. This means that the person involved should have legal capacity to give consent; should be so situated as to be able to exercise free power of choice, without the intervention of any element of force, fraud, deceit, duress, over-reaching, or other ulterior form of constraint or coercion; and should have sufficient knowledge and comprehension of the elements of the subject matter involved, as to enable him to make an understanding and enlightened decision. This latter element requires that, before the acceptance of an affirmative decision by the experimental subject, there should be made known to him the nature, duration, and purpose of the experiment; the method and means by which it is to be conducted; all inconveniences and hazards reasonably to be expected; and the effects upon his health or person, which may possibly come from his participation in the experiment.
    The duty and responsibility for ascertaining the quality of the consent rests upon each individual who initiates, directs or engages in the experiment. It is a personal duty and responsibility which may not be delegated to another with impunity.

  2. The experiment should be such as to yield fruitful results for the good of society, unprocurable by other methods or means of study, and not random and unnecessary in nature.

  3. The experiment should be so designed and based on the results of animal experimentation and a knowledge of the natural history of the disease or other problem under study, that the anticipated results will justify the performance of the experiment.

  4. The experiment should be so conducted as to avoid all unnecessary physical and mental suffering and injury.

  5. No experiment should be conducted, where there is an a priori reason to believe that death or disabling injury will occur; except, perhaps, in those experiments where the experimental physicians also serve as subjects.

  6. The degree of risk to be taken should never exceed that determined by the humanitarian importance of the problem to be solved by the experiment.

  7. Proper preparations should be made and adequate facilities provided to protect the experimental subject against even remote possibilities of injury, disability, or death.

  8. The experiment should be conducted only by scientifically qualified persons. The highest degree of skill and care should be required through all stages of the experiment of those who conduct or engage in the experiment.

  9. During the course of the experiment, the human subject should be at liberty to bring the experiment to an end, if he has reached the physical or mental state, where continuation of the experiment seemed to him to be impossible.

  10. During the course of the experiment, the scientist in charge must be prepared to terminate the experiment at any stage, if he has probable cause to believe, in the exercise of the good faith, superior skill and careful judgement required of him, that a continuation of the experiment is likely to result in injury, disability, or death to the experimental subject.

[“Trials of War Criminals before the Nuremberg Military Tribunals under Control Council Law No. 10”, Vol. 2, pp. 181-182. Washington, D.C.: U.S. Government Printing Office, 1949.]

The first principle of the Nuremberg Code included a new need to get active, informed consent. At the time this was a radical idea.  And it was not simply enough to gain consent.  People must understand the nature of the research they are agreeing to and must also know why the research is being done. Another ‘novel’ addition was the ninth principle which stated the right of people to withdraw from research. Additionally, the code makes it a duty of scientists to act in the best interests of those who take part in research (principles 8 and 10) and for the good of society (principle 2 and 6). Principles 1 and 9 gives people the rights to protect themselves and gives them as much authority as researchers. The final sentence of the first principle is maybe the most important. It states that duties and responsibilities cannot ‘be delegated to another with impunity’.  Claiming that one was merely ‘following orders’ was no longer an excuse.

In the years following the publication of the Nuremberg Code much research has failed to achieve these high standards.  For example, in the Tuskegee Syphilis study, African-American men who were diagnosed with syphilis were never told they were infected.   And even when penicillin became the standard cure in 1947 they were not treated and remained unaware objects of clinical study. Despite this, it is still difficult to understate the importance of the Nuremberg code for the conduct of all research involving human participants. Its impact on global human-rights law and research ethics has been profound and widespread. The first principle of informed consent has been comprehensively accepted and is incorporated into Article 7 of the United Nations International Covenant on Civil and Political Rights (1966). Versions of the Nuremberg Code can be found in the ethical codes, used by professional bodies and institutions.

Considering the Doctors’ Trial serves as a warning about how a lack of ethical standards can lead to dark places. Within the recent past, the American Psychological Association, changed its ethical code to allow psychologists to abandon some ethical responsibilities if they conflicted with military orders or other legal authorities. This effectively ditched a key principle of the Nuremberg code. The involvement of psychologists in sites such as Guantánamo Bay Detainment Camp and the Abu Ghraib prison should be a cause of great concern to all health professionals. The Nuremberg Code’s rule that researchers have duties and responsibilities that cannot be delegated came at such a high price that they should never be set aside.