Hitler's order for Action T4
|Also known as||T4 Program|
|Date||September 1939 – August 1941|
|Incident type||Forced euthanasia|
Action T4 (German: Aktion T4, pronounced [akˈtsi̯oːn teː fiːɐ]) was the postwar designation for a programme of forced euthanasia in wartime Nazi Germany. The name T4 is an abbreviation of Tiergartenstraße 4, a street address of the Chancellery department set up in spring 1940 in the Berlin borough of Tiergarten, which recruited and paid personnel associated with T4. Under the programme German physicians were directed to sign off patients "incurably sick, by critical medical examination" and then administer to them a "mercy death" (German: Gnadentod). In October 1939 Adolf Hitler signed a "euthanasia decree" backdated to 1 September 1939 that authorized Reichsleiter Philipp Bouhler, the chief of his Chancellery, and Dr. Karl Brandt, Hitler's personal physician, to carry out the programme of involuntary euthanasia (translated as follows):
Reich Leader Bouhler and Dr. Brandt are entrusted with the responsibility of extending the authority of physicians, designated by name, so that patients who, on the basis of human judgment [menschlichem Ermessen], are considered incurable, can be granted mercy death [Gnadentod] after a definitive diagnosis. — Adolf Hitler 
The programme ran officially from September 1939 to August 1941, during which the recorded 70,273 people were killed at various extermination centres located at psychiatric hospitals in Germany and Austria.
Several rationales for the programme have been offered, including eugenics, compassion, reducing suffering, racial hygiene, cost effectiveness and pressure on the welfare budget. After the formal end date of the programme, physicians in German and Austrian facilities continued many of the practices that had been instituted under Action T4, until the defeat of Germany in 1945. The unofficial continuation of the policy led to additional deaths by medicine and similar means; resulting in 93,521 beds "emptied" by the end of 1941. Historians estimate that twice the official number of T4 victims might have perished before the end of the war, exceeding 200,000. In addition, technology that was developed under Action T4, particularly the use of lethal gas to commit mass murder, was subsequently taken over by the medical division of the Reich Interior Ministry, along with transfer of personnel who had participated in the development of the technology and later served with Operation Reinhard. This technology, the personnel and the techniques developed to deceive victims were used in the implementation of industrial killings in mobile death vans, and in established extermination camps with gas chambers for mass murder during the Holocaust.
- 1 Language
- 2 Background
- 3 Implementation
- 4 Killing of children
- 5 Killing of adults
- 6 Gassing
- 7 Technology and personnel transfer to death camps
- 8 The official number of victims
- 9 Voices of opposition
- 10 Post-war history
- 11 Memorials
- 12 See also
- 13 Notes
- 14 References
- 15 External links
Euthanasia (from Greek: εὐθανασία; "good death": εὖ, eu; "well" or "good" – θάνατος, thanatos; "death") is the practice of intentionally ending a life in order to relieve pain and suffering. Hitler's directive to create the programme used the German term "Gnadentod" which translates to merciful death.
The Aktion T4 programme used the term 'euthanasia' as bureaucratic cover and in the minimal public relations efforts (see poster) to invest what was essentially an outgrowth of eugenics with greater medical legitimacy. Rather, the bulk of the evidence — including faked death certificates, deception of the victims and of the victims' families, and widespread use of cremation — indicates the killing was done solely according to the socio-political aims and beliefs of the perpetrators.
The T4 programme stemmed from the Nazi Party's policy of "racial hygiene", the belief that the German people needed to be "cleansed" of so-called racial enemies, which included people with disabilities as well as anyone confined to a mental health facility. The 'euthanasia' programme was a major step in the evolution of policy that culminated in the extermination of the Jews of Europe during the Holocaust. Hitler's ideology had embraced the enforcement of "racial hygiene" from its outset. In his book Mein Kampf (1924), Hitler wrote that one day the task: "will appear as a deed greater than the most victorious wars of our present bourgeois era."
The idea of sterilising those carrying hereditary defects or exhibiting what was thought to be hereditary "antisocial" behaviour was widely accepted. The United States, Sweden, Switzerland and other countries also passed laws authorizing sterilization of certain classes of people. For example, between 1935 and 1975 Sweden sterilised 63,000 people on eugenic grounds.
The policy and research agenda in racial hygiene and eugenics were actively promoted by Emil Kraepelin. The eugenic sterilization of persons diagnosed with (and viewed as predisposed to) schizophrenia was advocated by Eugene Bleuler who presumed racial deterioration because of mental and physical cripples in his Textbook of Psychiatry:
The more severely burdened should not propagate themselves… If we do nothing but make mental and physical cripples capable of propagating themselves, and the healthy stocks have to limit the number of their children because so much has to be done for the maintenance of others, if natural selection is generally suppressed, then unless we will get new measures our race must rapidly deteriorate.
The Nazis began to implement "racial hygiene" policies as soon as they came to power. The July 1933 "Law for the Prevention of Hereditarily Diseased Offspring" prescribed compulsory sterilisation for people with a range of conditions thought to be hereditary, such as schizophrenia, epilepsy, Huntington's chorea and "imbecility". Sterilisation was also mandated for chronic alcoholism and other forms of social deviance. The law was administered by the Interior Ministry under Wilhelm Frick through special Hereditary Health Courts (Erbgesundheitsgerichte), which examined the inmates of nursing homes, asylums, prisons, aged-care homes, and special schools to select those to be sterilised.
It is estimated that 360,000 people were sterilised under this law between 1933 and 1939. Within the Nazi administration, some suggested that the programme should be extended to people with physical disabilities, but such ideas had to be expressed carefully, given that one of the most powerful figures of the regime, Joseph Goebbels, had a deformed right leg. After 1937 the acute shortage of labour in Germany, arising from the demands of the crash rearmament programme, meant that anyone capable of work was deemed to be "useful" and thus exempted from the law. The rate of sterilisation declined.
Both his physician, Dr. Karl Brandt, and the head of the Reich Chancellery, Hans Lammers, testified after the war that Hitler had told them as early as 1933 – at the time when the sterilisation law was passed – that he favoured the killing of the incurably ill, but recognised that public opinion would not accept this. In 1935 Hitler told the Leader of Reich Doctors, Gerhard Wagner, that the question could not be taken up in peacetime: "Such a problem could be more smoothly and easily carried out in war." He wrote that he intended to 'radically solve' the problem of the mental asylums in such an event.
Although officially started in September 1939, Action T4 was initiated with a 'trial' case in late 1938. Hitler instructed his personal physician Karl Brandt to evaluate a family's petition for the "mercy killing" of their blind, physically and developmentally disabled boy. The child, born near Leipzig and identified as Gerhard Kretschmar eventually, was killed in July 1939. Hitler instructed Brandt to proceed in the same manner in all similar cases. Three weeks after the killing of the boy, the Reich Committee for the Scientific Registering of Hereditary and Congenital Illnesses was established on 18 August 1939. It was to prepare and proceed with the registration of sick children or newborns identified as defective. Secret killing of infants began in 1939 and increased after the war started. By 1941 more than 5,000 children had been killed.
Hitler was in favour of killing those whom he judged to be "unworthy of life". In a 1939 conference with health minister Leonardo Conti and the head of the Reich Chancellery, Hans Lammers – a few months before the 'euthanasia' decree – Hitler gave as examples the mentally ill who he said could only be "bedded on sawdust or sand" because they "perpetually dirtied themselves" and "put their own excrement into their mouths." This issue, according to the Nazi regime, assumed new urgency in wartime. After the invasion of Poland the leading Nazi doctor, Dr. Hermann Pfannmüller, said: "It is unbearable to me that the flower of our youth must lose their lives at the front while that feeble-minded and asocial element can have a secure existence in the asylum". Pfannmüller advocated gradual decrease of the food rations rather than death by medicine, which he believed was more merciful than poison injections.
The German eugenics movement had an extreme wing even before the Nazis came to power. As early as 1920, Alfred Hoche and Karl Binding advocated killing those whose lives were "unworthy of life" (lebensunwertes Leben). Darwinism was interpreted by them as justification of the demand for "beneficial" genes and eradication of the "harmful" ones. Historian Robert Lifton noted: "The argument went that the best young men died in war, causing a loss to the Volk of the best available genes. The genes of those who did not fight (the worst genes) then proliferated freely, accelerating biological and cultural degeneration".
The advocation of eugenics in Germany gained ground after 1930, when the Depression caused sharp cuts in funding to state mental hospitals, creating squalor and overcrowding. Most German eugenicists were already strongly nationalist and anti-Semitic, and embraced the Nazi regime with enthusiasm. Many were appointed to positions in the Health Ministry and German research institutes. Their ideas were gradually adopted by the majority of the German medical profession, from which Jewish and communist doctors were soon purged.
During the 1930s the Nazi Party carried out a campaign of propaganda in favour of "euthanasia". The National Socialist Racial and Political Office (NSRPA) produced leaflets, posters and short films to be shown in cinemas, pointing out to Germans the cost of maintaining asylums for the incurably ill and insane. These films included The Inheritance (Das Erbe, 1935), The Victim of the Past (Opfer der Vergangenheit, 1937), which was given a major première in Berlin and was shown in all German cinemas, and I Accuse (Ich klage an, 1941), which was based on a novel by consultant for 'child euthanasia' Hellmuth Unger.
Killing of children
In mid-1939 Hitler authorized the creation of the Reich Committee for the Scientific Registering of Serious Hereditary and Congenital Illnesses (Reichsausschuss zur wissenschaftlichen Erfassung erb- und anlagebedingter schwerer Leiden), headed by Dr. Karl Brandt, his personal physician, and administered by Herbert Linden of the Interior Ministry as well as SS-Oberführer Viktor Brack. Brandt and Bouhler were authorized to approve applications to kill children in relevant circumstances, though Bouhler left the details to subordinates such as Brack and SA-Oberführer Werner Blankenburg.
Extermination centres were established at six existing psychiatric hospitals: Bernburg, Brandenburg, Grafeneck, Hadamar, Hartheim, and Sonnenstein. They played a crucial role in developments leading to the Holocaust. As a related aspect of the "medical" and scientific basis of this programme, the Nazi doctors took thousands of brains from 'euthanasia' victims for research.
From August 1939 the Interior Ministry began registering children with disabilities, requiring doctors and midwives to report all cases of newborns with severe disabilities; the 'guardian' consent element soon disappeared. Those to be killed were identified as "all children under three years of age in whom any of the following 'serious hereditary diseases' were 'suspected': idiocy and Down syndrome (especially when associated with blindness and deafness); microcephaly; hydrocephaly; malformations of all kinds, especially of limbs, head, and spinal column; and paralysis, including spastic conditions". The reports were assessed by a panel of medical experts, of whom three were required to give their approval before a child could be killed.
The Ministry used various deceptions when dealing with parents or guardians particularly in Catholic areas, where parents were generally uncooperative. Parents were told that their children were being sent to "Special Sections" for children, where they would receive improved treatment. The children sent to these centres were kept for "assessment" for a few weeks and then killed by injection of toxic chemicals, typically phenol; their deaths were recorded as "pneumonia". Autopsies were usually performed, and brain samples were taken to be used for "medical research". This apparently helped to ease the consciences of many of those involved, since it gave them the feeling that the children had not died in vain, and that the whole programme had a genuine medical purpose.
Once war broke out in September 1939, the programme adopted less rigorous standards of assessment and a quicker approval process. It expanded to include older children and adolescents. The conditions covered also expanded and came to include
"various borderline or limited impairments in children of different ages, culminating in the killing of those designated as juvenile delinquents. Jewish children could be placed in the net primarily because they were Jewish; and at one of the institutions, a special department was set up for 'minor Jewish-Aryan half-breeds'".
At the same time, increased pressure was placed on parents to agree to their children being sent away. Many parents suspected what was really happening, especially when it became apparent that institutions for children with disabilities were being systematically cleared of their charges, and refused consent. The parents were warned that they could lose custody of all their children, and if that did not suffice, the parents could be threatened with call-up for 'labour duty'. By 1941 more than 5,000 children had been killed. The last child to be killed under Action T4 was Richard Jenne on 29 May 1945 in the children's ward of the Kaufbeuren-Irsee state hospital in Bavaria, Germany, more than three weeks after troops from the U.S. had occupied the town.
Killing of adults
Brandt and Bouhler soon developed plans to expand the programme of euthanasia to adults. In July 1939 they held a meeting attended by Dr. Leonardo Conti, Reich Health Leader and state secretary for health in the Interior Ministry, and Professor Werner Heyde, head of the SS medical department. This meeting agreed to arranging a national register of all institutionalised people with mental illnesses or physical disabilities.
Invasion of Poland (1 September 1939)
The first adults with disabilities to be killed on a mass scale by the Nazi regime were not Germans, but Poles. They were shot by the SS men of Einsatzkommando 16, Selbstschutz and EK-Einmann under direct command of SS-Sturmbannführer Rudolf Tröger, with overall command by Reinhard Heydrich during the genocidal Operation Tannenberg in which 36,000–42,000 people including Polish children died before the end of 1939 in Pomerania. All hospitals and mental asylums of the Wartheland were emptied. The region was incorporated into Germany and earmarked for resettlement by Volksdeutsche following the German conquest of Poland. Notably, the technology for mass gassing of hospital patients had not been invented yet. In the Danzig (now Gdańsk) area, some 7,000 Polish patients of various institutions were shot, while 10,000 were killed in the Gdynia area. Similar measures were taken in other areas of Poland destined for incorporation into Germany. The first experiments with the gassing of patients were conducted in October 1939 at Fort VII in Posen (occupied Poznań), where hundreds of prisoners were killed by means of carbon monoxide poisoning in an improvised gas chamber developed by Dr Albert Widmann, chief chemist of the German Criminal Police (Kripo). In December 1939 Reichsführer of the SS, Heinrich Himmler, witnessed one of these gassings, ensuring that this invention would later be put to much wider uses.
The idea of killing adult mental patients soon spread from occupied Poland to adjoining areas of Germany, probably because Nazi Party and SS officers in these areas were most familiar with what was happening in Poland. These were also the areas where Germans wounded from the Polish campaign were expected to be accommodated, which created a demand for hospital space. The Gauleiter of Pomerania, Franz Schwede-Coburg, sent 1,400 patients from five Pomeranian hospitals to undisclosed locations in occupied Poland where they were shot. Likewise, the Gauleiter of East Prussia, Erich Koch, had 1,600 patients murdered out of sight. In all, more than 8,000 Germans were killed in this initial wave of killings carried out under the command of local officials, although Himmler certainly knew and approved of them.
The sole legal basis for the programme was a 1939 letter from Hitler, not a formal 'Führer's decree' which would carry the force of law. Hitler deliberately bypassed Health Minister Conti and his department, who might have raised questions about the legality of the programme. He entrusted it to his personal agents Bouhler and Brandt. The programme was administered by Viktor Brack and his staff from Tiergartenstraße 4 disguised as the "Charitable Foundation for Cure and Institutional Care" offices which served as the front. It was supervised by Bouhler and Brandt.
The officials in charge included Dr Herbert Linden, who had been heavily involved in the children's programme; Dr Ernst-Robert Grawitz, chief physician of the SS; and August Becker, an SS chemist. They personally selected doctors who were to carry out the operational part of the programme; based on political reliability as long-term Nazis, professional reputation, and known sympathy for radical eugenics. The list included physicians who had proved their worth in the child-killing programme, such as Unger, Heinze, and Hermann Pfannmüller. The new recruits were mostly psychiatrists, notably Professor Carl Schneider of Heidelberg, Professor Max de Crinis of Berlin and Professor Paul Nitsche from the Sonnenstein state institution. Heyde became the operational leader of the programme, succeeded later by Nitsche.
Listing of targets from hospital records
In early October all hospitals, nursing homes, old-age homes and sanatoria were required to report all patients who had been institutionalised for five years or more, who had been committed as "criminally insane", who were of "non-Aryan race", or who had been diagnosed with any of a list of specified conditions. These included schizophrenia, epilepsy, Huntington's chorea, advanced syphilis, senile dementia, paralysis, encephalitis and "terminal neurological conditions generally". Many doctors and administrators assumed that the purpose of the reports was to identify inmates who were capable of being drafted for "labour service". They tended to overstate the degree of incapacity of their patients, to protect them from labour conscription – with fatal consequences. When some institutions refused to co-operate, teams of T4 doctors (or in some cases Nazi medical students) visited them and compiled their own lists, sometimes in a very haphazard and ideologically motivated way. At the same time, during 1940 all Jewish patients were removed from institutions and killed.
As with the child inmates, the adult cases were assessed by a panel of experts, working at the Tiergartenstraße offices. The experts were required to make their judgments solely on the basis of the reports, rather than on detailed medical histories, let alone examinations. Sometimes they dealt with hundreds of reports at a time. On each they marked a + (meaning death), a - (meaning life), or occasionally a ? meaning that they were unable to decide. Three "death" verdicts condemned the person concerned. As with reviews of children, over time these processes became less rigorous, the range of conditions considered "unsustainable" grew broader, and zealous Nazis further down the chain of command increasingly made decisions on their own initiative.
The first gassings in Germany proper took place in January 1940 at the Brandenburg Euthanasia Centre. The operation was headed by Viktor Brack, who said: "the needle belongs in the hand of the doctor." Bottled pure carbon monoxide gas was used. At trials, Brandt described the process as a "major advance in medical history". Once the efficacy of the method was confirmed, it became standardised, and instituted at a number of centres across Germany under the supervision of Widmann, Becker, and Christian Wirth – a Kripo officer who later played a prominent role in the extermination of the Jews as commandant of newly built death camps in occupied Poland. In addition to Brandenburg, the killing centres included Grafeneck Castle in Baden-Württemberg (10,824 dead), Schloss Hartheim near Linz in Austria (over 18,000 dead), Sonnenstein Euthanasia Centre in Saxony (15,000 dead), Bernburg Euthanasia Centre in Saxony-Anhalt and Hadamar Euthanasia Centre in Hesse (14,494 dead). The same facilities were also used to kill mentally sound prisoners transferred from concentration camps in Germany, Austria and occupied parts of Poland.
Condemned patients were 'transferred' from their institutions to newly built centres in the T4 Charitable Ambulance buses, called the Community Patients Transports Service. They were run by teams of SS men wearing white coats, to give it an air of medical care. To prevent the families and doctors of the patients from tracing them, the patients were often first sent to transit centres in major hospitals, where they were supposedly assessed. They were moved again to "special treatment" (Sonderbehandlung) centres. Families were sent letters explaining that owing to wartime regulations, it was not possible for them to visit relatives in these centres. Most of these patients were killed within 24 hours of arriving at the centres, and their bodies cremated. For every person killed, a death certificate was prepared, giving a false but plausible cause of death. This was sent to the family along with an urn of ashes (random ashes, since the victims were cremated en masse). The preparation of thousands of falsified death certificates took up most of the working day of the doctors who operated the centres.
During 1940 the centres at Brandenburg, Grafeneck and Hartheim killed nearly 10,000 people each, while another 6,000 were killed at Sonnenstein. In all, about 35,000 people were killed in T4 operations that year. Operations at Brandenburg and Grafeneck were wound up at the end of the year, partly because the areas they served had been cleared and partly because of public opposition. In 1941, however, the centres at Bernburg and Sonnenstein increased their operations, while Hartheim (where Wirth and Franz Stangl were successively commandants) continued as before. As a result, another 35,000 people were killed before August 1941, when the T4 programme was officially shut down by Hitler. Even after that date, however, the centres continued to be used to kill concentration camp inmates: eventually some 20,000 people in this category were killed.
In 1971 the Austrian-born journalist Gitta Sereny conducted a series of interviews with Franz Stangl, who was in prison in Düsseldorf after having been convicted of co-responsibility for killing 900,000 people as commandant of the Sobibor and Treblinka extermination camps in Poland. Stangl gave Sereny a detailed account of the operations of the T4 programme based on his time as commandant of the killing facility at the Hartheim institute. He described how the inmates of various asylums were removed and transported by bus to Hartheim. Some were in no mental state to know what was happening to them, but many were perfectly sane, and for them various forms of deception were used. They were told they were at a special clinic where they would receive improved treatment, and were given a brief medical examination on arrival. They were induced to enter what appeared to be a shower block, where they were gassed with carbon monoxide (this ruse was later used on a much larger scale at the extermination camps).
Technology and personnel transfer to death camps
After the official end of the euthanasia programme in 1941, most of the personnel and high-ranking officials, as well as gassing technology and the techniques used to deceive victims, were transferred under the jurisdiction of the national medical division of the Reich Interior Ministry. Further gassing experiments with the use of mobile gas-chambers (Einsatzwagen) were conducted at Soldau concentration camp by Herbert Lange following Operation Barbarossa. Lange was appointed commander of the Chełmno extermination camp in December 1941. He was given three gas vans by the RSHA, converted by the Gaubschat GmbH in Berlin, and already before February 1942 killed a total of 3,830 Polish Jews and around 4,000 Gypsies under the guise of "resettlement". After the Wannsee conference, the knowledge acquired in the process was then put to use by Reinhard Heydrich in the deadliest phase of the Holocaust. Beginning in spring 1942 three industrial killing centres were built secretly in east-central Poland. The SS officers responsible for the Aktion T4, including Christian Wirth, Franz Stangl, and Irmfried Eberl, were all given key roles in the implementation of the "Final Solution" for the next two years. The first killing centre equipped with stationary gas chambers modelled on Action T4 was established at Bełżec in the General Government territory of occupied Poland. Notably, the decision preceded the Wannsee Conference of January 1942 by three months.
The official number of victims
|Victims of Action T4 (official data), 1940 – September 1941|
|T4 Center||operation||number of victims|
|Grafeneck||20 January 1940||December 1940||9,839||---||9,839|
|Brandenburg||8 February 1940||October 1940||9,772||---||9,772|
|Bernburg||21 November 1940||30 July 1943||---||8,601||8,601|
|Hartheim||6 May 1940||December 1944||9,670||8,599||18,269|
|Sonnenstein||June 1940||September 1942||5,943||7,777||13,720|
|Hadamar||January 1941||31 July 1942||---||10,072||10,072|
|total by year:||35,224||35,049||70,273|
|Source: Document 87, P. 232 cit. in Ernst Klee. Dokumente zur "Euthanasie", 1985.|
Voices of opposition
In January 1939 Viktor Brack commissioned a paper from Professor of Moral Theology at the University of Paderborn, Joseph Mayer, on the likely reactions of the churches in the event of a state euthanasia programme being instituted. Mayer – a longstanding euthanasia advocate – reported that the churches would not oppose such a programme if it was seen to be in the national interest. Brack showed this paper to Hitler in July, and it may have increased his confidence that the "euthanasia" programme would be acceptable to German public opinion. Notably, when Gitta Sereny interviewed Mayer shortly before his death in 1967, he denied that he formally condoned the killing of people with disabilities, but no copies of this paper are known to survive.
There were those who opposed the T4 programme within the bureaucracy. Lothar Kreyssig, a district judge and member of the Confessing Church, wrote to Gürtner protesting that the action was illegal since no law or formal decree from Hitler had authorised it. Gürtner replied, "If you cannot recognise the will of the Führer as a source of law, then you cannot remain a judge", and had Kreyssig dismissed. Hitler had a fixed policy of not issuing written instructions for policies relating to what could later be condemned by international community, but made an exception when he provided Bouhler and Brack with written authority for the T4 programme in his confidential letter of October 1939 in order to overcome opposition within the German state bureaucracy. Hitler told Bouhler at the outset that "the Führer's Chancellery must under no circumstances be seen to be active in this matter." The Justice Minister, Franz Gürtner, had to be shown Hitler's letter in August 1940 to gain his cooperation.
The outbreak of war
In the towns where the killing centres were located, many people saw the inmates arrive in buses, saw the smoke from the crematoria chimneys and noticed that the buses were returning empty. In Hadamar, ashes containing human hair rained down on the town. The T4 programme was no secret. Despite the strictest orders, some of the staff at the killing centres talked about what was going on. In some cases families could tell that the causes of death in certificates were false, e.g. when a patient was claimed to have died of appendicitis, even though his appendix had been surgically removed some years earlier. In other cases, several families in the same town would receive death certificates on the same day. In May 1941 the Frankfurt County Court wrote to Gürtner describing scenes in Hadamar where children shouted in the streets that people were being taken away in buses to be gassed.
During 1940 rumours of what was taking place spread, and many Germans withdrew their relatives from asylums and sanatoria to care for them at home – often with great expense and difficulty. In some places doctors and psychiatrists co-operated with families to have patients discharged, or, if the families could afford it, had them transferred to private clinics where the reach of T4 did not extend. Other doctors agreed to "re-diagnose" some patients so that they no longer met the T4 criteria. This risked exposure when the Nazi zealots from Berlin conducted inspections. In Kiel, Professor Hans Gerhard Creutzfeldt managed to save nearly all of his patients. However, for the most part doctors co-operated with the programme, either from ignorance of its true meaning, agreement with Nazi eugenicist policies, or fear of the regime.
During 1940 protest letters were sent to the Reich Chancellery and the Ministry of Justice, some of them from Nazi Party members. The first open protest against the removal of people from asylums took place at Absberg in Franconia in February 1941, and others followed. The SD report on the incident at Absberg noted that "the removal of residents from the Ottilien Home has caused a great deal of unpleasantness", and described large crowds of Catholic townspeople, among them Party members, protesting against the action.
Others who privately protested were the Lutheran theologian Friedrich von Bodelschwingh, director of the Bethel Institution for epileptics at Bielefeld and Pastor Paul-Gerhard Braune, director of the Hoffnungstal Institution near Berlin. Both used their connections with the regime to negotiate exemptions for their institutions: Bodelschwingh negotiated directly with Brandt and indirectly with Hermann Göring, whose cousin was a prominent psychiatrist. Braune had meetings with Justice Minister Gürtner, who was always dubious about the legality of the programme. Gürtner later wrote a strongly worded letter to Hitler protesting against it; Hitler did not read it, but was told about it by Lammers. In general, the leaders of the Protestant church were more enmeshed with the Nazi regime than was the case for Catholics and they were unwilling to criticise its actions.
The Catholic Church, which since 1933 had pursued a policy of avoiding confrontation with the Nazi regime in the hope of preserving its core institutions, became increasingly unable to keep silent in the face of mounting evidence about the killing of inmates of hospitals and asylums. During 1940 and 1941 some Protestant churchmen protested privately against T4, but none made any public comment. Bishop Theophil Wurm, presiding the Evangelical-Lutheran Church in Württemberg, wrote a strong letter to Interior Minister Frick in March 1940. On 4 December 1940 Reinhold Sautter, Supreme Church Councillor of Württemberg's State Church, reproached the Nazi Ministerial Councillor Eugen Stähle for the murders in Grafeneck Castle. Stahle retorted with the Nazi government opinion, that "The fifth commandment: Thou shalt not kill, is no commandment of God but a Jewish invention" and no longer had any validity.
In July 1941 the Church broke its silence when a pastoral letter from the bishops was read out in all churches, declaring that it was wrong to kill (except in self-defence or in a morally justified war). This emboldened Catholics to make more outspoken protests. Leading Catholic churchmen, led by Cardinal Michael von Faulhaber of Munich, wrote privately to the government protesting against the policy. The Bishop of Münster, August von Galen, accused the government of breaking the law and publicly condemned the policy. Likewise, theologian Bernhard Lichtenberg protested to the Nazis chief medical officer. The regime took the program underground. Hitler recommended caution in Catholic areas, which after the annexations of Austria and the Sudetenland in 1938 included nearly half the population of Greater Germany. In March 1940 a confidential report from the SD in Austria warned that the killing programme must be implemented with stealth "in order to avoid a probable backlash of public opinion during the war".
A few weeks after the pastoral letter was read out, the Catholic Bishop of Münster in Westphalia, Clemens August Graf von Galen, publicly denounced the T4 programme in a sermon. He telegrammed his text to Hitler, calling on
"the Führer to defend the people against the Gestapo". "It is a terrible, unjust and catastrophic thing when man opposes his will to the will of God", Galen said. "We are talking about men and women, our compatriots, our brothers and sisters. Poor unproductive people if you wish, but does this mean that they have lost their right to live?" 
Historian Robert Lifton noted that the sermon might have had a greater impact than any other statement in consolidating the anti-'euthanasia' sentiment because it was dropped by British Royal Air Force pilots among German troops.
Another Bishop, Franz Bornewasser of Trier, also sent protests to Hitler, though not publicly. In August Galen was even more outspoken, broadening his attack to include the Nazi persecution of religious orders and the closing of Catholic institutions. He attributed the heavy Allied bombing of Westphalian towns to the wrath of God against Germany for breaking His laws. Galen's sermons were not reported in the German press but were widely circulated in the form of illegally printed leaflets. Local Nazis asked for Galen to be arrested but Goebbels told Hitler that such action would provoke open revolt in Westphalia.
By August the protests had spread to Bavaria. According to Gitta Sereny, Hitler was jeered by an angry crowd at Hof – the only time he was opposed in public during his 12 years of rule. Despite his private fury, Hitler knew that he could not afford a confrontation with the Church at a time when Germany was engaged in a life-and-death war, a belief which was reinforced by the advice of Goebbels, Martin Bormann, head of the Party Chancellery and SS leader Heinrich Himmler. Robert Lifton writes: "Nazi leaders faced the prospect of either having to imprison prominent, highly admired clergymen and other protesters – a course with consequences in terms of adverse public reaction they greatly feared – or else end the programme." Himmler said: "If operation T4 had been entrusted to the SS, things would have happened differently", because "when the Führer entrusts us with a job, we know how to deal with it correctly, without causing useless uproar among the people."
On 24 August 1941 Hitler ordered the cancellation of the T4 programme. He issued strict instructions to the Gauleiters to avoid further provocations of the churches for the duration of the war. The invasion of the Soviet Union in June provided new opportunities to use the T4 personnel. Many were transferred to the east to begin work on a vastly greater programme of killing: the "final solution of the Jewish question". The winding-up of the T4 programme did not end the killing of people with disabilities. From the end of 1941, the killing became less systematic. Lifton documents that the killing of adults and children continued to the end of the war, on the local initiative of institute directors and party leaders. The methods reverted to those employed before use of the gas chambers: lethal injection or starvation. Kershaw estimates that by the end of 1941 some 75,000 to 100,000 people had been killed in the T4 programme. Tens of thousands of concentration camp inmates and people judged incapable of work, were killed in Germany between 1942 and 1945. This figure does not include Jews who were deported to their deaths in Action Reinhard of 1942 and 1943. The Hartheim and Hardamar centres continued to kill people sent to them from all over Germany until 1945.
In December 1946 an American military tribunal (commonly called the Doctors' trial) prosecuted 23 doctors and administrators for their roles in war crimes and crimes against humanity. These crimes included the systematic killing of those deemed "unworthy of life", including the mentally disabled, the institutionalized mentally ill, and the physically impaired. After 140 days of proceedings, including the testimony of 85 witnesses and the submission of 1,500 documents, in August 1947 the court pronounced 16 of the defendants guilty. Seven were sentenced to death and executed on 2 June 1948. They included Dr. Karl Brandt and Viktor Brack.
The indictment read in part:
14. Between September 1939 and April 1945 the defendants Karl Brandt, Blome, Brack, and Hoven unlawfully, willfully, and knowingly committed crimes against humanity, as defined by Article II of Control Council Law No. 10, in that they were principals in, accessories to, ordered, abetted, took a consenting part in, and were connected with plans and enterprises involving the execution of the so called "euthanasia" program of the German Reich, in the course of which the defendants herein murdered hundreds of thousands of human beings, including German civilians, as well as civilians of other nations. The particulars concerning such murders are set forth in paragraph 9 of count two of this indictment and are incorporated herein by reference.
Earlier, in 1945, American forces tried seven staff members of the Hadamar killing centre for the killing of Soviet and Polish nationals, which was within their jurisdiction under international law, as these were the citizens of wartime allies. (Hadamar was within the American Zone of Occupation in Germany. This was before the December 1945 Allied resolution supporting prosecution of "crimes against humanity" for such mass atrocities.) Alfons Klein, Karl Ruoff and Wilhelm Willig were sentenced to death and executed; the other four were given long prison sentences. In 1946, newly reconstructed German courts tried members of the Hadamar staff for the murders of nearly 15,000 German citizens at the facility. Adolf Wahlmann and Irmgard Huber, the chief physician and the head nurse, were convicted.
- August Becker, initially sentenced to three years after the war, in 1960 was tried again and sentenced to 10 years in prison. He was released early due to ill-health and died in 1967.
- Werner Blankenburg lived under an alias and died in 1957.
- Philipp Bouhler committed suicide in captivity, May 1945.
- Werner Catel was cleared by a de-nazification board after World War Two and was head of pediatrics at the University of Kiel. He retired early after his role in the T4 program came to light.
- Leonardo Conti hanged himself in captivity, 6 October 1945.
- Dr Ernst-Robert Grawitz killed himself shortly before the fall of Berlin in April 1945.
- Dr. Herbert Linden committed suicide in 1945. Overseers of the program were initially Herbert Linden and Werner Heyde. Linden was later replaced by Hermann Paul Nitsche.
- Dr. Fritz Cropp d. 6 April 1984, Bremen. A Nazi official, in 1933, in Oldenburg, Cropp was appointed the country medical officer of health. Two years later, in 1935, he transferred to Berlin, where he worked as a ministerial adviser in the Division IV (health care and people care) in the Ministry of the Interior. In 1939, he became Assistant Director. Fritz Cropp was involved in the Nazi "euthanasia", the so-called action T-4, in 1940. He was Herbert Linden's superior. He was responsible for patient transfers.
- Dr Werner Heyde, after having escaped detection for 18 years, killed himself in 1964 before being brought to trial.
- Dr Heinrich Gross was tried twice. One sentence was overturned and another was suspended; he died in 2005.
- Lorenz Hackenholt vanished in 1945.
- Erich Koch served time in prison from 1950 to his death in 1986.
- Erwin Lambert died in 1976.
- Dr. Friedrich Mennecke died in 1947 while awaiting trial.
- Philipp, Landgrave of Hesse, the governor of Hesse-Nassau, was not tried for his part in the T4 programme; he died in 1980.
- Paul Nitsche was tried and executed by an East German court in 1948.
- Professor Carl Schneider hanged himself in his prison cell in 1946, while awaiting trial.
- Franz Schwede was sentenced to 10 years in prison in 1948 and was pardoned in 1956; he died in 1960.
- Dr. Ernst Illing was the director of the Vienna Psychiatric-Neurological Clinic for Children Am Spielgrund, where he killed about 200 children, sentenced to death on 18 July 1946
- Dr. Marianne Türk was a doctor at Vienna Psychiatric-Neurological Clinic for Children Am Spielgrund where, together with Ernst Illing, she killed 200 children. She was sentenced to 10 years prison on 18 July 1946.
The Ministry for State Security of East Germany stored around 30,000 files of the T4 project in their archives. Those files became available to the public only after the German Reunification in 1990, leading to a new wave of research on these wartime crimes.
The German national memorial to the people with disabilities murdered by the Nazis was dedicated in 2014 in Berlin. It is located in the pavement of a site next to the Tiergarten park, the location of the former villa at Tiergartenstrasse 4 in Berlin, where more than 60 Nazi bureaucrats and doctors worked in secret under the "T4" program to organize the mass murder of sanatorium and psychiatric hospital patients deemed unworthy to live.
- Proctor 1988, p. 191.
- Sandner (1999): 385 (66 in PDF) Note 2. The author claims the term Action T4 was not used by the Nazis but was first used in the trials against the doctors and later included in the historiography. (German)
- Artur Hojan & Cameron Munro (2015). "Overview of Nazi 'euthanasia' program". The central office at Tiergartenstrasse 4 in Berlin. The Tiergartenstrasse 4 Association. Retrieved 28 August 2015 – via Nazi Ideology and Ethics By Wolfgang Bialas & Lothar Fritze, pp. 263, 281; ISBN 1443858811.
- Sereny 1983, p. 48. Tiergartenstraße 4 was the location of the Central Office and administrative headquarters of the Gemeinnützige Stiftung für Heil- und Anstaltspflege (literally, "Charitable Foundation for Curative and Institutional Care").
- Proctor (1988): 177
- This was the Kanzlei des Führer der NSDAP, not to be confused with the Reich Chancellery or Reichskanzlei.
- Miller (2007), 160.
- Lifton 1986, pp. 63-64. The "euthanasia decree" in translation.
- Peter Longerich, Holocaust: The Nazi Persecution and Murder of the Jews, p. 477 – note 44
- Browning (2005): p. 193
- Burleigh, Michael, and Wolfang Wippermann (2014). "Nazi Racial Science". United States Holocaust Memorial Museum United States Holocaust Memorial Museum.
- Mark B. Adams Associate Professor of the History and Sociology of Science University of Pennsylvania (1990). The Wellborn Science: Eugenics in Germany, France, Brazil, and Russia. Oxford University Press. pp. 40, 84, 191.
- Ryan & Schuchman 2002, p. 25. The Nuremberg Military Tribunal evidence. Note 34.
- Lifton (1986): p. 95-96
- Lifton (1986): p. 142.
- Michael Burleigh (1994), Death and Deliverance: 'Euthanasia' in Germany, C.1900 to 1945 CUP Archive, ISBN 0521477697.
- Ryan & Schuchman 2002, p. 62. Estimated range between 200,000 and 250,000 unofficial victims of policy upon the arrival of Allied troops in Germany.
- Robert Jay Lifton (2000). The Nazi Doctors: Medical Killing and the Psychology of Genocide. New York: Basic Books. p. 102. ISBN 0465049052. Retrieved 2 June 2015.
- Sereny 1983, p. 54. Role of T4 "Inspector" Christian Wirth in the Holocaust.
- Philosopher Helga Kuhse: "'Euthanasia' is a compound of two Greek words - 'eu' and 'thanatos' meaning, literally, 'a good death'. Today, 'euthanasia' is generally understood to mean the bringing about of a good death - 'mercy killing,' where one person, A, ends the life of another person, B, for the sake of B." — Euthanasia fact sheet. A more extensive definition and analysis with references is contained in the Stanford Encyclopedia of Philosophy: Euthanasia entry.
- Lifton 1986, p. 64.
- Breggin, Peter (1993). "Psychiatry's role in the holocaust" (PDF file, direct download from the Internet Archive, 4.07 MB). International Journal of Risk & Safety in Medicine 4 (2): 133–148. doi:10.3233/JRS-1993-4204. PMID 23511221.
- Hitler, Mein Kampf, 447 (cited by Peter Padfield, Himmler, Macmillan 1990, 260)
- Evans, 514
- Engstrom EJ, Weber MM, Burgmair W (October 2006). "Emil Wilhelm Magnus Georg Kraepelin (1856–1926)". The American Journal of Psychiatry 163 (10): 1710. doi:10.1176/appi.ajp.163.10.1710. PMID 17012678.
- Joseph, Jay (2004). The Gene Illusion: Genetic Research in Psychiatry and Psychology Under the Microscope. Algora Publishing. p. 160. ISBN 0875863442.
- Bleuler E. (1924). Textbook of Psychiatry. New York: Macmillan. p. 214. See: Read J, Masson J (2004). "Genetics, eugenics and mass murder". In Read J, Mosher RL, Bentall RP. Models of Madness: Psychological, Social and Biological Approaches to Schizophrenia. Hove, East Sussex: Brunner-Routledge. p. 36. ISBN 1583919058.
- Evans, 507
- Evans (2005): 508
- This was the result either of club foot or osteomyelitis. Goebbels is commonly said to have had club foot (talipes equinovarus), a congenital condition. William L. Shirer, who worked in Berlin as a journalist in the 1930s and was acquainted with Goebbels, wrote in The Rise and Fall of the Third Reich (1960) that the deformity was from a childhood attack of osteomyelitis and a failed operation to correct it.
- Kershaw, II, 256
- Friedman (2011), p. 146 note 12
- Lifton thinks this request was "encouraged"; the severely disabled child and the agreement of the parents to his killing were apparently genuine (Lifton (1986): 50)
- Schmidt (2007): 118
- Stephen J. Cina, Joshua A. Perper, When Doctors Kill, p. 59
- Lifton (1986): pp. 50–51
- Proctor (1988): p. 10; Browning, 190.
- Lifton 1986, p. 62.
- Lifton (1986): pp. 62, 63; quoted in Gerhard Schmidt, Selektion in der Heilanstalt 1939–1945 (Stuttgart: Evangelisches Verlagsanstalt, 1965), p. see pp. 34-35. Hermann Pfannmüller, original text in German: Für mich ist die Vorstellung untragbar, dass beste, blühende Jugend an der Front ihr Leben lassen muss, damit verblichene Asoziale und unverantwortliche Antisoziale ein gesichertes Dasein haben. – From: Gerhard Baader, Psychiatrie im Nationalsozialismus p. 18/27 in PDF, note 66.
- Their ideas were published in The Permission to Destroy Life Unworthy of Life (Die Freigabe der Vernichtung lebensunwerten Lebens), 1920
- Lifton 1986, p. 47.
- Kershaw, II, 254
- The ready acceptance of Nazi ideas by the majority of the German medical profession is described in Evans, 444
- Lifton 1986, pp. 48-49.
- Browning (2005): 185
- Kershaw, II, 259
- Miller (2007), 158
- Fuller Torrey, Edwin; Yolken, Robert (January 2010). "Psychiatric genocide: Nazi attempts to eradicate schizophrenia". Schizophrenia Bulletin 36 (1): 26–32. doi:10.1093/schbul/sbp097. PMC 2800142. PMID 19759092. Retrieved 28 March 2012.
- Weindling, Paul Julian (2006). Nazi Medicine and the Nuremberg Trials: From Medical War Crimes to Informed Consent. Palgrave Macmillan. p. 6. ISBN 0-230-50700-X.
- Lifton 1986, p. 52.
- These were Professor Werner Catel (a Leipzig psychiatrist); Professor Hans Heinze, head of a state institution for children with intellectual disabilities at Görden near Brandenburg; Ernst Wentzler a Berlin pediatric psychiatrist; and the author Dr. Helmut Unger. (Lifton (1986): 52)
- Sereny 1983, p. 55.
- Lifton 1986, p. 60.
- Lifton 1986, p. 56.
- Lifton 1986, p. 55.
- Browning, 190. Lifton concurs with this figure, but notes that the killing of children continued even after the T4 programme was formally ended in 1941.
- Henry Friedlander (1995). The Origins of Nazi Genocide: From Euthanasia to the Final Solution University of North Carolina Press, 1995. p. 163.
- Suzanne E. Evans. Forgotten crimes: the Holocaust and people with disabilities. p. 93. Retrieved 25 July 2011.
- Semków 2006, pp. 46–48. The second phase of Operation Tannenberg referred to as the Unternehmen Tannenberg by Heydrich's Sonderreferat began in late 1939 under the codename Intelligenzaktion and lasted until January 1940.
- Piotr Semków, IPN Gdańsk (September 2006). "Kolebka (Cradle)" (PDF). IPN Bulletin No. 8–9 (67–68), 152 pages (Warsaw: Institute of National Remembrance). 42–50 (44–51/152 in PDF). ISSN 1641-9561. Retrieved 8 November 2015 – via direct download: 3.44 MB.
- Friedlander (1995): p. 87.
- Browning, 186–187.
- Browning, 188
- Browning, 190, Kershaw, II, 261
- Lifton 1986, pp. 63, 64. Several drafts of a formal euthanasia law were prepared, but Hitler refused to authorise them. Thus, the senior participants in the programme always knew that it was not a law even by the loose definition of legality prevailing in Nazi Germany.
- Padfield, 261
- Kershaw, II, 253
- Lifton 1986, p. 66.
- Lifton, 67
- Browning, 191, Padfield, 261, 303, Lifton (1986): 77. According to Lifton, most Jewish inmates of German mental institutions were dispatched to Lublin in Poland in 1940 and killed there.
- George J. Annas, and Michael A. Grodin (1992). The Nazi Doctors and the Nuremberg Code: Human Rights in Human Experimentation. Oxford University Press. p. 25. ISBN 0199772266 – via Google Books, preview.
- Lifton, 71
- Lifton 1986, p. 72.
- Burleigh, Michael (2000): p.54
- Lifton 1986, p. 74.
- These figures come from the article Aktion T4 on the German Wikipedia, which sources them to Ernst Klee, "Euthanasie" im SS-stadt: Die "Vernichtung lebensunwerten Leben" ("Euthanasia" in the SS-state: The extermination of "life unworthy of life"), Frankfurt, 1983
- Sereny 1983, pp. 41–90.
- Mathias Beer (translated from the German) (2015). "The Development of the Gas-Van in the Murdering of the Jews". The Final Solution. Jewish Virtual Library. "Die Entwicklung der Gaswagen beim Mord an den Juden," Miszelle. Vierteljahrshefte fuer Zeitgeschichte, 37 (3), pp. 403-417. Retrieved 27 June 2015.
- WUW (2013). Ringelblum Archives of the Holocaust. Introduction (PDF file, direct download). Wydawnictwa Uniwersytetu Warszawskiego. p. 20 (xx). Retrieved May 13, 2013.
- Historia Niemieckiego Obozu Zagłady w Bełżcu (History of the Belzec extermination camp) (in Polish), Muzeum - Miejsce Pamięci w Bełżcu (National Bełżec Museum & Monument of Martyrology), retrieved 24 May 2015
- Sereny 1983, p. 71.
- Lifton 1986, p. 75.
- Sereny 1983, p. 58.
- Lifton 1986, p. 82. Creutzfeldt is also remembered as the co-discoverer of Creutzfeldt-Jakob disease
- Lifton 1986, p. 80. Lifton lists a handful of psychiatrists and administrators who actively opposed the T4 programme.
- Lifton 1986, p. 90.
- Lifton 1986, pp. 90-92.
- Sereny 1983, pp. 69, 74.
- Schmuhl (1987): p. 321.
- Kershaw, II, 427
- Ten Catholic Heroes-of-the Holocaust CatholicHerald.co.uk.
- THE RESPONSE OF THE GERMAN CATHOLIC CHURCH TO NATIONAL SOCIALISM yadvashem.org
- Padfield, 304
- Lifton 1986, p. 93.
- Lifton 1986, p. 94.
- Kershaw, II, 429
- Sereny 1983, p. 59. Sereny did not claim first-hand knowledge of this event. It is apparently based on testimony given by Dr Friedrich Mennecke during a postwar trial. According to Mennecke, Hitler was traveling between Munich and Berlin when his train suddenly stopped at a station. A crowd was watching a group of "retarded patients" being loaded into a train. Seeing Hitler at the window, the crowd became threatening. Mennecke apparently told this as an "anecdote" rather than something he knew to be true.
- Lifton 1986, Footnote 1.
- Lifton 1986, p. 95.
- Lifton 1986, pp. 96-102.
- "Transcription". United States Holocaust Museum.
- "Captured German Records" (PDF). National Archives and Records Administration.
- Ernst Klee: Fritz Cropp, Eintrag in ders.: Das Personenlexikon zum Dritten Reich. Wer war was vor und nach 1945. Aktualisierte Ausgabe. Fischer-Taschenbuch-Verlag, Frankfurt am Main 2005, ISBN 3-596-16048-0, S. 98
- Berenbaum: p. 247
- Totten & Parsons (2009): 181 ss.
- Horst von Buttlar:Forscher öffnen Inventar des Schreckens at Spiegel Online (1 October 2003) (German)
- ABC News. "International News - World News - ABC News". ABC News.
- "Berlin Dedicates Holocaust Memorial for Disabled - Global Agenda - News - Arutz Sheva". Arutz Sheva.
- Bachrach, Susan D; Kuntz, Dieter; United States Holocaust Memorial Museum (2004). Deadly Medicine: Creating the Master Race. Washington D.C.:United States Holocaust Memorial Museum: Chapel Hill, NC : Distributed by the University of North Carolina Press. ISBN 0-8078-2916-1.
- Benzenhöfer, Udo (2010). Euthanasia in Germany Before and During the Third Reich. Münster/Ulm: Verlag Klemm & Oelschläger. ISBN 978-3-86281-001-7 – via Google Books, no preview.
- Berenbaum, Michael; Peck, Abraham J. The Holocaust and History: The Known, the Unknown, the Disputed, and the Reexamined. ISBN 0253215293.
- Browning, Christopher (2005). The Origins of the Final Solution: The Evolution of Nazi Jewish Policy, September 1939 – March 1942. Arrow. ISBN 978-0-8032-5979-9.
- Burleigh, Michael (1995). Death and Deliverance: 'Euthanasia' in Germany 1900–1945. New York: Verlag Klemm + Oelschläger. ISBN 978-0521477697.
- Burleigh, M. & Wippermann, W. (1991). The Racial State: Germany 1933–1945. Cambridge University Press.
- Burleigh, Michael (2000). "Psychiatry, German Society and the Nazi "Euthanasia" Programme". In Omer Bartov. The Holocaust Origins, Implementation, Aftermath. London: Routledge. p. 54. ISBN 0-415-15036-1.
- Evans, Richard J. (2005). The Third Reich in Power. Allen Lane.
- Friedlander, Henry (1995). The Origins of Nazi Genocide. From Euthanasia to the Final Solution. University of North Carolina Press, Chapel Hill & London. ISBN 0-8078-2208-6.
- Friedman, Jonathan C. (2011). The Routledge History of the Holocaust. Routledge. p. 516. ISBN 0-203-83744-4.
- Klee, Ernst (1985). Dokumente zur Euthanasie (in German). Frankfurt am Main: Fischer Taschenbuch Verlag. ISBN 3-596-24327-0.
- Klee, Ernst (1983). Euthanasie im NS-Staat. Die Vernichtung lebensunwerten Lebens (in German). Frankfurt am Main: Fischer Taschenbuch Verlag. ISBN 3-596-24326-2.
- Klee, Ernst (1986). Was sie taten. Was sie wurden: Ärzte, Juristen und andere Beteiligte am Kranken- oder Judenmord (in German). Fischer Taschenbuch. p. 355. ISBN 3-596-24364-5.
- Lifton, Robert Jay MD (1986). The Nazi Doctors: Medical Killing and the Psychology of Genocide. New York: Basic Books. Full contents, 561 pages. ISBN 0-465-04904-4 – via Holocaust-history.org (online version).
- Miller, Michael (2007), Leaders of the SS and German Police, Vol. 1, R. James Bender Publishing, ISBN 93-297-0037-3 – via Amazon (no preview)
- Ost, Suzanne (April 2006). "Doctors and nurses of death: a case study of eugenically motivated killing under the Nazi 'euthanasia' programme". Liverp Law Rev 27 (1): 5–30. doi:10.1007/s10991-005-5345-2. PMID 17340766.
- Padfield, Peter (1990). Himmler: Reichsführer-SS. Macmillan. ISBN 978-0-333-40437-9.
- Proctor, Robert N. (1988). Racial Hygiene: Medicine under the Nazis. Library of Congress: Harvard College. See: 414 (Postwar Legacies). ISBN 0-674-74578-7 – via Google Books, preview.
- Ryan, Donna F.; Schuchman, John S. (2002). Racial Hygiene: Deaf People in Hitler's Europe. Patricia Heberer, "Targetting the Unfit". Gallaudet University Press. ISBN 978-1-56368-132-5 – via Google Books, preview.
- Sandner, Peter (July 1999). "Die "Euthanasie"-Akten im Bundesarchiv. Zur Geschichte eines lange verschollenen Bestandes" (PDF). Vierteljahrschefte für Zeitgeschichte – Institut für Zeitgeschichte (Munich, Germany)) 47 (3): 385–400. ISSN 0042-5702.
- Schmidt, Ulf (2007). Karl Brandt: The Nazi Doctor. Hambledon Continuum.
- Schmuhl, Hans-Walter (1987). Rassenhygiene, Nationalsozialismus, Euthanasie: Von der Verhütung zur Vernichtung "lebensunwerten Lebens", 1890–1945 (Kritische Studien zur Geschichtswissenschaft Bd. 75) (in German). Göttingen: Vandenhoeck & Ruprecht,. p. 526. ISBN 3-525-35737-0. Note: simultaneously handed in as doctoral thesis in Bielefeld, University of Bielefeld, Diss., 1986 under the title: Die Synthese von Arzt und Henker
- Sereny, Gitta (1983). Into that darkness: an examination of conscience. Vintage Books. 400 pages. ISBN 978-0-394-71035-8.
- Werthman, Fredric (1967). A Sign for Cain. New York: MacMillan and Company. ISBN 978-0-02-625970-5.
- Thompson, D. (2004). "Axis History Forum. The Nazi Euthanasia Program".
- Totten, Samuel; Parsons, William S. (2009). Century of genocide: critical essays and eyewitness accounts (Third ed.). New York: Routledge. ISBN 978-0-415-99084-4.
- BBC (1997), The Nazis: A Warning from History (internal link), television documentary
- Joanna Mack (dir.), Channel 4 (22 October 1991), Selling Murder: The Killing Films of the Third Reich, Domino Films / Channel 4 (UK television), tx. includes excerpts from Opfer der Vergangenheit and Ich klage an
- Astrid Ley, Annette Hinz-Wessels (editors), The "Euthanasia Institution" of Brandenburg an der Havel. – Murder of the ill and handicapped during National Socialism, ISBN 978-3-86331-086-8
|Wikimedia Commons has media related to Action T4.|
- Website with photo of Philipp Bouhler and facsimile of Hitler's letter to Bouhler and Brandt authorising the T4 programme
- The complete text of Robert Lifton's The Nazi Doctors online
- List of Action T-4 personnel
- United States Holocaust Memorial Museum Final Solutions: Murderous Racial Hygiene 1939–1945
- United States Holocaust Memorial Museum Euthanasia programme
- Non-Jewish Victims of Persecution in Germany – About the Holocaust – Yad Vashem
- Nazis euthanasia files made public by the BMJ/British Medical Association: files relating to the 200,000 euthanasia crimes
- Holocaust Studies, personal story.Holocaust Studies: My Cousin Karlchen
- A Report by Disability Rights Advocates in Arabic.A Report by Disability Rights Advocates in Arabic