The main trial at Nuremberg after World War II was conducted by the International Military Tribunal. The tribunal was made up of judges from the four allied powers (the United States, Britain, France, and the former Soviet Union) and was charged with trying Germany's major war criminals. After this first-of-its-kind international trial, the United States conducted 12 additional trials of representative Nazis from various sectors of the Third Reich, including law, finance, ministry, and manufacturing, before American Military Tribunals, also at Nuremberg. The first of these trials, the Doctors' Trial, involved 23 defendants, all but 3 of whom were physicians accused of murder and torture in the conduct of medical experiments on concentration-camp inmates.7

The indictment of the defendants was filed on October 25, 1946, 25 days after the conclusion of the first Nuremberg trial by the International Military Tribunal. The Doctors' Trial began on December 9, 1946, and ended on July 19, 1947. The case was heard by three judges and one alternate. Thirty-two prosecution witnesses and 53 defense witnesses, including the 23 defendants, testified. A total of 1471 documents were introduced into the record. Sixteen of the 23 defendants were found guilty; 7 of them were sentenced to death by hanging, 5 to life imprisonment, 2 to imprisonment for 25 years, 1 to imprisonment for 15 years, and 1 to imprisonment for 10 years. Seven were acquitted. The sentences were confirmed by the military governor, and, after the U.S. Supreme Court declined to review the case, the executions were carried out at the Landsberg prison.

For the United States and its chief prosecutor, Telford Taylor, the trial was a murder trial (and murder had been identified by the International Military Tribunal as a crime against humanity). Nonetheless, as Taylor pointed out in his opening statement, this was “no mere murder trial,” because the defendants were physicians who had sworn to “do no harm” and to abide by the Hippocratic Oath.12 He told the judges that the people of 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.”12 One recurring theme was the relevance of Hippocratic ethics to human experimentation and whether Hippocratic moral ideals could be an exclusive guide to the ethics of research without risk to the human rights of subjects. In the trial's exploration of ideas that shaped medical-research ethics, three physicians had central roles: Leo Alexander, an American neuropsychiatrist, Werner Leibbrand, a German psychiatrist and medical historian, and Andrew Ivy, a renowned American physiologist.

Leo Alexander

Leo Alexander, a Viennese-born American physician, had joined the U.S. Army Medical Corps in 1942, before being stationed in England at the American Eighth Air Force base. At the end of the war, Alexander was sent on a special mission under the Combined Intelligence Objectives Sub-Committee, an intelligence organization with members from several nations, and charged by orders from Supreme Headquarters of Allied Expeditionary Forces to gather evidence for the Nuremberg trials. Two days before the opening of the Doctors' Trial, Alexander gave Taylor a memorandum entitled “Ethical and Non-Ethical Experimentation on Human Beings,” in which he identified three ethical, legal, and scientific requirements for the conduct of human experimentation.9 The first requirement established the right of the competent experimental subject to consent or refuse to participate in these terms: “the subject should be willing to undergo the experiment of his own free will. . . .” The second focused on the duty of physicians as expressed in the Hippocratic Oath, which Alexander restated in research terms: “the medical Hippocratic attitude prohibits an experiment if the foregone conclusion, probability or a priori reason to believe exists that death or disabling injury of the experimental subject will occur.” The third characterized good research practices.

On April 15, 1947, Alexander gave Taylor a second memorandum.9,11 In it he set forth in greater detail six specific conditions for ethically and legally permissible experiments on human beings. The first stated that

the legally valid voluntary consent of the experimental subject is essential. This requires specifically the absence of duress, sufficient disclosure on the part of the experimenter and sufficient understanding on the part of the experimental subject of the exact nature and consequences of the experiment for which he volunteers, to permit an enlightened consent.

The five other conditions established the humanitarian nature and purpose of the experiment and the scientific integrity and obligations of the investigator to the welfare of the subject.

Werner Leibbrand

On January 27, 1947, Werner Leibbrand, a German psychiatrist and medical historian at Erlangen University, opened the debate on medical ethics at Nuremberg.12 He explained to the court that German physicians at the beginning of the 20th century had adopted a “biologic thinking” according to which a patient was a series of biologic events, and nothing more than “a mere object, like a mail package.”12 Leibbrand insisted that such a view precluded any human relation between physicians and their patients and that it represented a perversion of Hippocratic ethics and “a lack of morality and reverence for human life.”12 He strongly condemned physicians who conducted experiments on subjects without their consent, and testified that this was also the result of biologic thinking.

During cross-examination, defense lawyers asserted that “civilized” nations such as France, the Netherlands, Britain, and the United States had performed dangerous medical experiments on prisoners, often without their consent. They cited American malaria experiments12-14 to argue that Nazi physicians had followed common research practices. Leibbrand replied that this American research also was wrong because “prisoners were in a forced situation and could not be volunteers.”12 Leibbrand insisted that “the morality of a physician is to hold back his natural research urge which may result in doing harm, in order to maintain his basic medical attitude that is laid down in the Oath of Hippocrates.”12 This strong accusation of American research by the prosecution's first medical-ethics witness created major unanticipated problems for the prosecution. It therefore became necessary to broaden the scope of the trial by defining the conditions under which risky human experimentation is ethically permissible.

Defense lawyers explained that Nazi doctors were ordered by the state to conduct such experiments as the high-altitude, hypothermia, and seawater experiments on inmates at the Dachau concentration camp to determine how best to protect and treat German fliers and soldiers. They contended that these experiments were necessary and that the “good of the state” takes precedence over that of the individual.12 Leibbrand replied that “the state could order deadly experiments on human subjects, but the physicians remained responsible for [not] carrying them out.”12 Once these physiologic experiments became the centerpiece of the trial, reliance on psychiatrists alone was not possible. The prosecution needed a prestigious medical scientist who was an authority on research physiology and whose wartime scientific interests corresponded to those of the Nazi doctor defendants. This expert was Andrew Ivy.

Andrew Ivy

Andrew Ivy was an internationally known physiologist and a noted scientist. He also had first-hand knowledge of the Stateville Penitentiary experiments on malaria12,13 in his home state of Illinois, which the Nazi defendants attempted to liken to those performed on concentration-camp inmates. When the secretary of war, through the surgeon general of the army, asked the board of trustees of the American Medical Association to nominate a medical advisor to the Nuremberg prosecution, Ivy emerged as the natural nominee. On June 12, 1947, Ivy came to Nuremberg for the third time, this time to testify in rebuttal for the prosecution. His testimony, the longest of the trial, lasted four days.12

In direct examination, Ivy presented to the judges three research principles that he had formulated at the request of the American Medical Association and which, he said, reflected common research practices.12 His document entitled “Principles of Ethics Concerning Experimentation with Human Beings,” adopted by the American Medical Association House of Delegates in December 1946, read in part:

1. Consent of the human subject must be obtained. All subjects have been volunteers in the absence of coercion in any form. Before volunteering, subjects have been informed of the hazards, if any. Small rewards in various forms have been provided as a rule. 2. The experiment to be performed must be based on the results of animal experimentation and on a knowledge of the natural history of the disease under study, and must be so designed that the anticipated results will justify the performance of the experiment. The experiment must be such as to yield results for the good of society, unprocurable by other methods of study, and must not be random and unnecessary in nature. 3. The experiment must be conducted only by scientifically qualified persons and so as to avoid all unnecessary physical and mental suffering and injury and only after the results of adequate animal experimentation have eliminated any a priori reason to believe that death or disabling injury will occur. . . .15

Ivy explained that these common-sense principles mirrored the understanding shared by everyone in practice in the medical community.12 The first principle was that a physician would never do anything to a patient or subject before obtaining his or her consent. Ivy also asserted that, unlike Leibbrand, he did not consider prisoners to be in an inherently coercive situation and thus unable to give consent, because in democratic countries where the rights of individuals are respected, prisoners can always say yes or no without fear of being punished.12 He testified:

The American malaria experiments with 800 or more prisoners were absolutely justified, scientifically, legally and ethically even if they bring with them danger to human life. To treat malaria was an important scientific problem, and so long as the subjects volunteer and are explained the hazards of the experiments, there is no ethical reason against it. . . . If prisoners condemned to death are volunteers, then it was ethical to do just that.12

During cross-examination, Ivy acknowledged that there were no written principles of research in the United States or elsewhere before December 1946 and that the principles adopted by the American Medical Association were expressly formulated for the Doctors' Trial.12 Ivy also recognized that the right of the research subject to withdraw from an experiment may not always exist, as in the malaria experiments in which the subjects had already been infected, or in dangerous experiments in which the subjects could be severely injured or fatally harmed. Ivy agreed with Leibbrand that researchers must refuse to conduct experiments on human beings when ordered by the state in order “to save lives,” because in such cases subjects would not be volunteers. He declared that “[t]here is no justification in killing five people in order to save the lives of five hundred” and that “no state or politician under the sun could force [him] to perform a medical experiment which [he] thought was morally unjustified.”12 Ivy also stressed that the state may not assume the moral responsibility of physicians to their patients or research subjects, arguing that “[E]very physician should be acquainted with the Hippocratic Oath [which] represents the Golden Rule of the medical profession in the United States, and, to [his] knowledge, throughout the world.”12 When, finally, defense counsel asked Ivy to reconcile the Hippocratic moral maxim that forbids physicians to “administer a poison to anyone even when asked to do so” with conducting potentially lethal experimental interventions on volunteer subjects, Ivy replied, “I believe this Hippocratic commandment refers to the function of the physician as a therapist, not as an experimentalist, and what refers to the Hippocratic Oath is that he must have respect for life and the human rights of his experimental patient.”12