5.1 Introduction

Johann Weyer was the first physician to specialize in mental illness, redefining melancholics as mentally ill, not demonically possessed (Cavanaugh 2015). In 1808, Johann Christian Reil coined the term “psychiatry,” based on the Greek words psukhē (soul, mind) and iatreia (healing) (Lomax 2019; Gaebel et al. 2007). Starting in the late 1800s and early 1900s, large psychiatric institutions were founded, typically outside of metropolitan areas (Gaebel et al. 2007) as a mechanism to provide humane and holistic care (Strous 2007) to these patients. The next advancement in psychiatric care began with the work of multiple psychiatrists, Emil Kraepelin, Alois Alzheimer, and Carl Wernicke, who developed the foundational basis of the psychiatric diagnosis system (Gaebel et al. 2007), which was used to label those individuals medically considered inferior (Strous 2007). By the 1920s and until the end of World War II, governmental institutions, private financiers, and wealthy patrons, funded what was then contemporary psychiatric research (Roder et al. 1994). Psychiatrists became instrumental in differentiating what medicine and society defined as normal versus abnormal. Moreover, psychiatrists helped enact laws which defined psychiatric diagnoses and therapies as they subsequently became the agents who enforced these legislative mandates. Through their camouflage of social policies as medical science, and by broadening (what in retrospect is considered arbitrary) definition(s) of mental illness, they maintained and expanded their burgeoning influence on the medical profession (Roder et al. 1994).

The contemporary psychiatrist Dr. Rael Strous further describes how, during the Nazi era, this political influence allowed psychiatrists to systematically exterminate their patients. Although members of other medical specialties were also involved in this medical genocide, psychiatrists were among the worst transgressors (Strous 2007). Their professional participation in “identifying, notifying, transporting and killing…racially and cognitively compromised individuals…was central and critical to the success of Nazi policy, plans and principles” (Strous 2007, 1). This genocide “did not take place in a vacuum” (Friedlander 1995, 1). The concept of medicalization allowed psychiatry to attain an unprecedented professional status during the Nazi era and provided a framework for the classification, labeling and persecution of millions of individuals deemed unfit by this newly powerful group of professionals. Instead of actively or even passively resisting the ideology of medicalization, psychiatrists played a central role in what became known as “crimes against humanity” (Strous 2007, 2). In spite of parallel advancements in science (e.g., cancer research, biochemistry, and quantum mechanisms), ethical protections went awry (Strous 2007).

In addition, very few physicians had the ability to identify, circumvent or ameliorate their multiple conflicting obligations as members of the medical profession, the court system, the Volk and the political regime for the well-being of their patients. They even disregarded Germany’s sophisticated 1931 codes of medical ethics (Strous 2007). Instead, they provided leadership roles in bureaucratic genocide, such as the mass killings occurring in psychiatric facilities (e.g., Hadamar) and within industrial killing centers (e.g., Auschwitz). This is in contrast to their fallacious, post-war justifications that opposition to the State would result in the threat of their own execution (Roder et al. 1994).

5.2 The Paradigm Shifts

Historically there existed two traditions of medical care in Germany: individual-based and public health care. Economic pressures after World War I had a negative impact on earlier health care benefits and priorities which had emphasized the early detection of illness, relief of suffering, preventive care and occupational health. Post-war financial stressors and subsequent eugenical categorizations of patients created a system identifying those individuals deemed “unworthy” to receive governmental-supported health services. The ensuing reversal of moral priorities from those which emphasized Aesculapian, patient-centered interests to those which gave precedence to the health of society redefined the medical profession’s obligations to their patients (Reich 2001). This represented a critical paradigm shift away from the traditional Hippocratic methods focusing on the relationship between patient and doctor towards one in which the doctor’s foremost responsibility was to care for society. The repercussions of this crucial change in perspective would have disastrous outcomes for millions whose existence was not considered beneficial to the health of the nation. This transformation was felt not only in the field of medicine, but also in the political realm. In 1934, Rudolf Hess, the Deputy Führer to Hitler, went so far as to describe “National Socialism as nothing but applied biology” (Lifton 2000, 31).

The protection of the health of the “transcendental” Volk (albeit limited to a homogenous Aryan population) became the new, primary obligation of the physician (Lifton 2000). Specifically, in 1926, the professional code of German medicine asserted: “The profession of a doctor lies in health service for the German nation” (Pross and Aly 1991, 10). This misguided emphasis on the idiosyncratic primacy of the Volk (which was considered an “organism” in itself), professional empowerment and the corresponding belief the state was justified in determining which members of society were judged as productive, served as a perceived legitimate basis for the subsequent, selective exclusion and involuntary sterilization and the “eliminative genocide of the Holocaust” (Robertson et al. 2017, 66; Pross and Aly 1991; Lifton 2000; Strous 2007). This disruption of the prior relationship between physicians and patients was predicated on an opposition to the equality of men (Friedlander 1995). What began as a humanitarian, post-World War I effort to provide universal, state-funded health care, became politically tied to a biomedical vision based on ultra-nationalistic and militaristic goals as a mechanism to create a healthy German population (Bachrach 2004; Friedlander 1995). The Aryan population was unambiguously considered to be superior (Haque et al. 2012; Hofstadter 1992; Friedlander 1995). The developing, eugenic-based, definitional proof of inequality and “hostility toward the handicapped” (Friedlander 1995, 196), led to this misguided and unsound social policy. By creating the pretext of a eugenic biological “crisis,” the government could assume sovereign power over the lives of its citizens (Robertson et al. 2017).

Psychiatrists, many of whom represented senior members of academia, provided the theoretical foundation based on biology and heredity (Strous 2007). It was psychiatry that was the most involved in determining the hierarchy of human worth (Dudley and Gale 2002). As the “Nazi movement both absorbed and advanced this ideology” (Friedlander 1995, 1), psychiatrists, as part of the new scientific elite, provided the necessary legitimacy and ideological commitment to the Nazi regime (Friedlander 1995). Their involvement not only led to new career opportunities but placed those within the profession “close to the center of power” (Friedlander 1995, 196). Psychiatrists provided the necessary leadership, backing and oversight in the respective planning committees, which resulted in the successful implementation of political policies based on race (Strous 2007; Friedlander 1995). These committees created the medical and bureaucratic processes that would identify the targeted individuals. The harms associated with this ideology were further exacerbated when the interests of science (i.e., racial-hygiene) assumed priority over the autonomy of an individual patient. Over time, the psychiatric template for the Endlösung (Final Solution) became itself a “medical procedure” (Robertson et al. 2017, 70) that was used to legitimize the application of medical techniques as weapons against the most vulnerable members of humankind, and to support societally-sanctioned genocide.

5.3 Dehumanization and Degradation

Why did so many physicians willingly participate in the murder of their patients? How could those dedicated to healing abandon the Hippocratic Oath (Proctor 1992, 17) and transform into killers? Why were they complicit with the ingrained societal ideology? These questions become especially hard to answer as scholars remind us that ethics training was a required component of their medical curriculum (Bruns and Chelouche 2017).

In retrospect, it was not sufficient for German academics to teach the concept of eugenics to colleagues or students. Silencing dissenting voices was also not enough. Physicians needed to embrace this indoctrination as truth, so that the ideas and methodologies could be practically applied. The systematic implementation of racial hygiene theory required intentional cooperation and collaboration as a basis of consultation, politicization and enactment of “early national Socialist legislation” (Miller and Gallin 2019, 260). Psychiatric and neurologic communities were heavily influenced by Erwin Bauer, Eugen Fischer and Fritz Lenz’s 1921 textbook Human Heredity and Racial Hygiene. In their seminal writing, these three prominent geneticists not only described, but promoted the “scientific rationale for medically-sanctioned, eugenic sterilization programs” intended to protect the racial hygiene of society and the Volk (Miller and Gallin 2019, 267). For example, Lenz estimated ten to fifteen percent of the population was defective and could be candidates for sterilization (Proctor 1992, 21). This book became the foundational training for many psychiatrists and neurologists as they established eugenic practices advocating for the extermination of the unfit and reflected academia’s pioneering role in Hitler’s rise to power (Roder et al. 1994). Separately, the racial hygiene institutes within German universities and the “journals of racial hygiene…were established long before the rise of National Socialism” (Proctor 1992, 20–21).

The consequences of the mandatory racial-hygiene curriculum established in medical schools created the antecedent mechanism to academically justify dehumanizing members of society based on their defined social status. Historically, demonizing members of a society leads to dehumanization. This does not occur with a single event. Rather, it is a gradual process that includes the labeling, classification, debasement and persecution of individuals on the basis of their being defined as less than human. During the Nazi era, physicians had the moral imperative and required medical authority to protect the Volk via sterilization and ultimately the eugenic genocide of those considered to be unfit, or subhuman. These decisions were asserted to be immutable and based on empirical data. Dr. Robert Jay Lifton, a post—war psychiatrist, describes the process of Nazi physicians’ professional development. The German physician’s desired identity was based on the Renaissance physician, Paracelsus, who was noted for using his knowledge of chemistry in the field of medicine. Hippocrates was also considered a medical ideal from an earlier generation. Professionalism was further amplified to now include a primary, political obligation to the Volk, which would result in the larger healing of society (Lifton 2000). For example, Gerhard Wagner, a Nazi medical authority, claimed the life of the nation takes precedence over “dogma and conflicts of conscience” (Lifton 2000, 29). This politization is reflected by multiple German physicians who told Lifton, “the oath of loyalty to Hitler they took as SS military officers was much more real… than a vague ritual performed at medical school graduation” (Lifton 2000, 207).

As the medical system became politicized, the political system itself became more medicalized. Hence, the confluence of medicine and politics that proved deadly for so many. This transformed professional identity and allegiance replaced the Hippocratic Oath as the principal driving force behind Nazi medicine, creating a unique scenario that paved the way for healers to become killers (Miller and Gallin 2019).

5.4 Psychiatry Timeline—Kraepelin to Rüdin

Eugenics, which arose in the late nineteenth century was “considered to be the leading, cutting-edge science of the time” (Grodin et al. 2018, 54). Scientists and politicians, including those within the United States, worked together to implement mechanisms to decrease the prevalence of those defined as hereditarily weak (Grodin et al. 2018). Lifton quotes an anonymous physician who asserted, “physicians alone possess the necessary combination of theoretical knowledge and direct human experience to serve as authentic biological evangelists” (Lifton 2000, 31).

Emil Kraepelin, founder of the German Institute for Psychiatric Research, specialized in the study of hereditary factors in illness (Roder et al. 1994). Geneticists were concerned that society’s compassion would prevent natural selection, thus allowing pathological traits to flourish (Lifton 2000; JAMA 1933a). One of Kraepelin’s specific research interests was schizophrenia, and his work on this is still referenced in the Diagnostic and Statistical Manual (DSM) (Roder et al. 1994). Using this handbook, psychiatrists were instrumental in identifying individuals who displayed schizophrenic characteristics, which became one of the criteria for coercive sterilization (Strous 2007).

These ideas were further developed by Kraepelin’s student Ernst Rüdin (Roder et al. 1994). Rüdin was considered one of the major leaders and pioneers in German psychiatry and was, notably, financially supported by the Rockefeller Foundation (Torrey and Yolken 2010). He was an influential, first generation, racial hygienist, and the famed originator of psychiatric genetics (Bachrach 2004; Roder et al. 1994). He was also the co-founder of the German Society for Racial Hygiene, the Director of the Department of Heredity of the Kaiser-Wilhelm-Institute of Psychiatry, and the President of the Association of German Neurologists and Psychiatrists from 1933 to 1945 (Lifton 2000; Breggin 1993; Seidelman 1988; Lindert et al. 2012). In addition, Rüdin taught psychiatry at the University of Munich, where Mengele studied medicine (Seidelman 1988).

As early as 1911, Rüdin proposed eugenic legislation based on his population study exploring “Fortpflanzung, Vererbung, Rassenhygiene” (Procreation, Transmission, Racial Hygiene) (Roder et al. 1994, 43). These eugenic ideas were based on an interpretation of Darwin’s survival of the fittest within animal populations and Mendel’s laws of genetic transmission (Roder et al. 1994). Eugenics presumed that genetic purity and homogeneity were a definitional basis of this fitness (Ernst 2001). For instance, in 1935, Rüdin stated “the bases of all race hygiene were the preservation of the healthy hereditary elements and the eradication of the pathologic elements” (Seidelman 1988, 222). Rüdin’s colleagues Alfred Ploetz, (creator of the term ‘race hygiene’ (Rassenhygiene)) and his pupil, the geneticist Fritz Lenz, further influenced the medicalization of eugenic precepts by using genetics to justify racial inequality (Ernst 2001). In contrast to the political heterogeneity of the United States which encouraged diversity, German society and its political systems became more homogeneous and consolidated. Until the German defeat in World War I, the eugenicists initially focused on positive eugenics which encouraged increasing desirable traits in society through reproduction (Friedlander 1995). This history reveals it was the early German psychiatric-racial hygienists, not the Nazis, who were at the forefront of the movement to improve the racial health and hygiene of society (Roder et al. 1994).

Despite the fact that German medicine and Nazi ideology complemented each other, Rüdin had to wait for the eventual political empowerment of National Socialism for eugenic-based legislation to be passed by the Reichstag. The use of academic studies in human genetics provided the practical justifications for population policy (Pross and Aly 1991). Because physicians provided “the science and claim to authority of the medical field,” they could then be “mobilized to turn this vision into a reality” (Kelly et al. 2017, 99). It only took four months for the escalation to occur.

Although Germany approved legislation after WWI to permit voluntary sterilization, this initial legislation did not mandate involuntary sterilization (Grodin et al. 2018). It was not until 1933 that Rüdin was able to merge health and social policy by co-authoring the compulsory, surgical-sterilization “Law for the Prevention of Genetically Diseased Offspring” (Gesetz zur Verhütung erbkranken Nachwuchses (GVeN, July 14, 1933) (Torrey and Yolken 2010; Bachrach 2004; Grodin et al. 2018; Ernst 2001; Roder et al. 1994). This policy was inspired by American sterilization legislation created by Harry Laughlin (Truman State University 2021; Breggin 1993; Proctor 1992, 21). Although German law initially targeted individuals diagnosed with feeble-mindedness (e.g., mental retardation), schizophrenia, genetic epilepsy, manic-depressive disorders, hereditary blindness, hereditary deafness, chronic alcoholism, severe physical malformations, and Huntington’s chorea (Bachrach 2004; Grodin et al. 2018; Lindert et al. 2012; Lifton 2000), the “Law Against Dangerous Career Criminals,” passed in November 1934, was expanded to include “habitual criminals” and the “Law for the Alteration of the Law for the Prevention of Hereditarily Diseased Offspring,” passed in June 1935, allowed for involuntary abortion. These abortions could occur anytime during the first six months of pregnancy if the mother had a hereditary illness (Lindert et al. 2012). Physicians, as “advocates of the state,” could now “prosecute those…charged with being ‘genetically ill’” by regulating their reproduction (Pross and Aly 1991). Between 1934–1935, 388,400 individuals were identified as hereditarily suspect and referred to the Hereditary Health Courts in Berlin. The overwhelming number of individuals denounced by the referring health care personnel underwent involuntary sterilization (Friedlander 1995). These examples reveal how mandated sterilization was used as a medical weapon.

Furthermore, the psychiatrist Karl Bonhoeffer offered a course in 1934 describing a psychiatrist’s responsibilities in upholding this law. The impact of this legislation resulted in approximately 300,000 to 400,000 individuals undergoing involuntary sterilization, with 62,000 incidents in the first year alone. (Pross and Aly 1991; Kelly et al. 2017; Roder et al. 1994). Age was not a factor in implementing sterilization procedures: “The youngest reported victim of involuntary sterilization was two years old” (Meyer-Lindenberg 1991, 8). It wasn’t until after 1945 that this law was finally annulled in Germany (Pross and Aly 1991).

Not all eugenic sterilizations were based on traditional psychiatric diagnoses. For example, the September 1935 “Nuremberg Laws for the Protection of German Blood,” defined race as a category of eugenic control (Seidelman 1988, 223; Friedlander 1995, 11, 23–24). This legislation placed race in the purview of psychiatry, thus allowing psychiatrists to enforce eugenic sterilization using racial inferiority as a diagnosis. Moreover, conscientious objectors were targeted by eugenicists, with those who did not support war activities classified as schizophrenic. This “hereditary” condition became an independent criterion for sterilization (Seidelman 1988). Rüdin, during his 1935 address to the Society of German Neurologists and Psychiatrists, gave “credit to psychiatry for its role in improving racial hygiene,” (Seidelman 1988, 223) through its essential enforcement of eugenic sterilization.

Other essential roles of psychiatrists included adjudicating who was sterilized and educating the next generation of physicians. For example, two of Rüdin’s colleagues, Eugen Fischer and Otmar von Verschuer subsequently served as medical judges/racial experts for the newly convened Hereditary Health Courts (Seidelman 1988; Bachrach 2004; Pross and Aly 1991). In addition, Fischer and von Verschuer created the racial-science curriculum for SS physicians. In these legal and educational processes, theory became practice (Pross and Aly 1991). Further evidence of von Verschuer’s entanglement includes mentoring his first assistant in Frankfurt, Josef Mengele (Seidelman, pp. 224–225).

The concomitant sterilization efforts became part of a comprehensive racial hygiene program which also informed antimiscegenation laws (e.g., “Law for the Protection of German Blood and Marriages”) and led to the creation of hereditary data banks (Ernst 2001; Bachrach 2004). Once involuntary sterilization became normalized, physicians’ participation was no longer viewed as anomalous or wrong. This is an important point when trying to understand the psychological justifications given by Nazi doctors for their behaviors.

5.5 Sterilization Was not Enough

Once Hitler assumed power in 1933, any prior political opposition to eugenics was swept aside (Bachrach 2004). All professions were subject to a process of Gleichshaltun, whereby professional values were made to align with the authoritarian ideology of the Nazi regime (Robertson et al. 2017). Hitler advocated (Aryan) social unity even if this resulted in the dehumanization of German citizens. The contemporary theologian Professor Warren T. Reich notes:

“Gemeinnutz geht vor Eigennutz” (What is useful for the community has priority over what is useful for the individual) and “Du bist nichts, dein Volk ist alles” (You are nothing; your people [nation] is everything) (Haque et al. 2012, 477; Reich 2001, 64).

The primary theoretical underpinning of Gleichschaltung for German psychiatry was eugenics. The faulty genetic inheritance theories of Rüdin and his colleagues coincided with the international popularity of eugenics and the growing interest in Rassenhygiene (Racial Hygiene) within Germany (Robertson et al. 2017).

In 1913, there were an estimated 238,583 psychiatric inpatients in German psychiatric facilities (Torrey and Yolken 2010). By 1924–1929, the number of psychiatric hospital patients increased to over 300,000. These overcrowded asylums (e.g., sanatoria, nursing homes or care institutions) were the focal point of psychiatric clinical practice (Robertson et al. 2017). Psychiatrists, as part of their daily clinical routines, were exposed to the distressing extremes of aberrant human behavior(s). Correspondingly, there were minimal effective therapies which they could utilize as part of their treatment armamentarium. By the 1930s, psychiatric interventions appeared more promising, leading to the reform movement in psychiatry which prompted the optimistic exploration of research therapies including open care (Erlangen model), malaria therapy, aversion therapy and insulin coma therapy (Robertson et al. 2017; Lindert et al. 2012). In spite of these new therapeutic interventions, psychiatric illnesses and their associated disabilities remained irremediable and intractable (Robertson, 72), resulting in increased social norms of stigmatization, isolation and condemnation (Robertson et al. 2017; Strous 2010). Ineffective, non-curative medical therapies and lifelong institutionalization, combined with the perception of psychiatric illness as a biological threat to society, reinforced negative public views about the financial burdens associated with this patient population (Robertson et al. 2017; Torrey and Yolken 2010). The ultimate danger to the patient, however, was the immense power psychiatry wielded, compared to other medical specialties, to forcibly and involuntarily remove “undesirables from society and plac[ing] them in asylums” (Strous 2007, 7). Thus, a connection was forged between psychiatry and public health which allowed the medical profession to identify, denounce and remove those individuals whom society deemed unsuitable from the general public.

Prior to Hitler’s rise to power, Karl Binding, a renowned Professor of Law, and Alfred Hoche, the Freiburg Chair in Psychiatry, wrote the controversial 1920 academic treatise, Permission for the Destruction of Life Unworthy of Life, which promoted the idea of killing individuals labeled as lebensunwertes leben (life unworthy of life) (Lindert et al. 2012; Lifton 2000). The biological concept and designation of genetic inferiority provided the foundation for proposing the legalization of “mercy killing,” while the traditional concept of the sanctity of human life was ignored. Mercy killing, rationalized as a compassionate and “allowable, useful act,” became re-defined as a therapeutic, “healing” medical procedure (Lifton 2000, 46–47).

Although these were not initially mainstream views, Binding and Hoche imparted separate economic arguments, partially based on war reparations, to justify these proposed premature deaths (Gardella 1999; Strous 2010; Torrey and Yolken 2010; Lifton, 2000), stating “the burden on society by having to care for these individuals was too high and their human status too low” (Grodin et al. 2018, 54). Or, as Binding states: “Reflect…on a battlefield strewn with thousands of dead youths…Compare this with our mental hospitals, with their caring for the living inmates…the meticulous care shown to existences which are not just absolutely worthless but even of negative value” (Gardella 1999; Binding and Hoche 1920, 246). The idea that human beings were entitled to be treated with dignity and respect simply by virtue of being human instead was replaced by the notion that a person should be measured by his or her worth to society—a chilling economic argument that continues to have repercussions to this day.

If a mercy killing program was to be objectively implemented, Binding suggested the use of a team comprised of a general physician, a psychiatrist and a lawyer. The rationale for this proposal was that medical care of those without economic value to the Volk unjustifiably drained social resources, and any limited financial resources should instead be directed toward healthy men and women. This medical hubris was further validated by the untimely deaths of otherwise healthy German citizens, with their “best available genes,” during the previous war (Lifton 2000, 47).

Binding, a German jurist, described the physician’s legal responsibilities in “killing….consenting participants,” or in killing “incurable idiots” unable to consent as legally and moral permissible (Lifton 2000, 47). Binding and Hoche further described the need for a “carefully controlled judicial process” (Lifton 2000, 47) when applying for permission to perform euthanasia. Fidelity to the process would provide legal protection for physicians (Lifton 2000, 47). They argued that consent could not be a relevant factor because an “incurable idiot [is] unable to consent” (Lifton 2000, 47). More practically, consent would undermine the intentional secrecy of the program (Friedlander 1995). Hoche further noted “physicians must be protected against prosecution for euthanasia” (Friedlander 1995, 16).

Robert Jay Lifton recounts Hoche’s purported role as a “biological visionary” when Hoche stated: “A new age will come which, from the standpoint of a higher morality, will no longer heed the demands of an inflated concept of humanity and an overestimation of the value of life as such” (Lifton 2000, 47). Hitler and other Nazi officials ardently agreed with this concept. By 1931, Fritz Lenz noted “Hitler is the first politician…who has recognized that racial hygiene is a crucial political task and is prepared actively to support it” (Longerich 2019, 140). Immense power was thus given to doctors based on their ability to determine an individual’s worth to society. The trajectory of healers to killers began with this accumulation and consolidation of power.

Before 1939, “the majority of eugenicists and race hygienists did not support the systematic killing of the mentally handicapped…They believed that there were more effective means of preventing their reproduction” (Kuhl 2001, 185–186). Even after the First World War, the “majority of leading right-wing eugenicists and race hygienists drew a clear line between eugenic measures like sterilization and marriage prohibition, and the killing of the handicapped” (Kuhl 2001, 186). This was in contrast to Karl Binding’s and Alfred Hoche’s campaign to kill those not worthy of living. Initially, the eugenicists argued against incorporating euthanasia as a component of social reform programs. They argued sterilization would be a sufficient mechanism to reduce the production of inferior offspring and should not be used to terminate “already living people” (Kuhl 2001, 199).

The leaders of the eugenics movement, again, well before the Third Reich, were principal directors of the psychiatric institutes of the Kaiser Wilhelm Society. As noted by Thomas Roder, “the architects of the Holocaust … gathered in the psychiatric societies” (Roder et al. 1994, 159). Henry Friedlander further describes the publications of a German journalist, Ernst Klee, who provided a “detailed account of the so-called euthanasia program. Friedlander then recounts how the analyses by Benno Muller-Hill revealed how “euthanasia was not simply a prologue but the first chapter of Nazi genocide” (Friedlander 1995, XII). As the relative value of an individual life diminished, psychiatrists put eugenic principles into action, assuming their central role in the Nazi regimen’s euthanasia program. This abrogation of their primary responsibilities toward recognizing the ethical concept of human dignity diminished the moral stature not only of psychiatrists, but of all physicians.

5.6 The Importance of Eugenics for the War Machine

Between 1918 and 1924, Paul Weindling describes the progressive development of eugenic thought and practice, which began to advance the concept of “euthanasia” (Weindling 1989). In addition, Stefan Kuhl describes how the eugenicists argued that wars were dysgenic, based on the indiscriminate killing of “superior” individuals in the battlefields or by disease (Kuhl 2001). After World War I, eugenicists “saw their countries invaded by an ‘army of the unfit’… [which] included beggars, alcoholics, criminals, prostitutes, psychopaths, epileptics, mental invalids, feebleminded, and cripples” (Kuhl 2001, 198). This perspective further changed society’s compassion towards it most vulnerable members.

During a 1934 eugenics conference in Zurich, Rüdin argued that the “will for peace” was an important “common tie” between eugenicists. His colleague, Alfred Ploetz initiated a resolution against the “menace of war… (which) would again kill the most capable men” (Kuhl 2001, 200). In this international arena, this resolution politically linked Nazi race policies with the condemnation of contra-selective or dysgenic wars. The Nazi government hoped to commend and reward Ploetz’s “eugenic peace” efforts by nominating him for the Nobel peace prize in 1936 (Kuhl 2001).

Rüdin and his colleagues hoped that the biological mission of creating hereditarily healthy offspring would result in the utopian vision of “true peace” among the most capable. This vision was further echoed by Hitler. Eugen Stähle, a German internist and politician, further justified the Nazi killing program by stating: “If during the war we ask thousands of young and healthy people to sacrifice their lives for the community, we can ask the same sacrifice from the incurably ill” (Kuhl 2001, 202). This propaganda of “race policy as peace policy” became the ideological matrix and verbiage within which the Nazis justified the killing of its handicapped citizens (Kuhl 2001, 202).

World War II required a dissociative shift from eugenics as a “form of peace” to an escalation and intensification of eugenics as a form of race policy. Otmar von Verschuer, Eugen Fischer, Fritz Lenz, and Ernst Rüdin “saw the necessity not only for an economic and military mobilization, but especially for a biological one” (Kuhl 2001, 204–205). This resulted in a further radicalization of their race hygiene policy.

5.6.1 Euthanasia Decree: From Eugenics to Euthanasia

Beginning in February 1939, Hitler began his next phase of euthanasia in consultation with professors of neuropsychiatry and pharmacology to determine which method(s) should be used for killing (Meyer-Lindenberg 1991). In July 1939, as he was planning to invade Poland, Hitler asked his private physician and other officials to draft a law that permitted the heretofore, illegal killing of mental patients with mental disorders (Torrey and Yolken 2010; Strous 2007). In August 1939, approximately ten to fifteen expert psychiatrists, asylum directors and other key organizers met to discuss and advise the logistics of a euthanasia program (Schmidt 2007). On August 18, 1939, the German Ministry of the Interior created a “highly confidential” circular that ordered physicians and midwifes to report newborn babies with deformities (Longerich 2019; Pross and Aly 1991). These required documents were then sent to a centrally located post-office box in Berlin for review by the “National Committee for the Scientific Registration of Serious Hereditary and Congenital Diseases.” Three experts would then determine the subsequent actions regarding these children.

The physician-perpetrators needed legal protections if this policy was to be implemented. Hitler pivoted, and forbade the creation of explicit legislation as an “unrealistic solution during war” (Friedlander 1995, 188). Instead, Professor Max de Crinis, a senior academic T4 psychiatrist and SS member, was thought to have provided wording to Hitler for what became the written authorization known as the “euthanasia” decree (Lindert et al. 2012; Schmidt 2007). Professor de Crinis was considered “the most outspoken and influential Nazi within the German psychiatric establishment” (Lifton 2000, 120). He knew a verbal order to psychiatrists authorizing killing was insufficient for this task (Friedlander 1995). Soon after Warsaw’s capitulation on September 17, 1939, Hitler dictated a memo to Karl Brandt and Reichsleiter Philipp Bouhler on his personal letterhead and backdated it to September 1, 1939, to correspond with the beginning of the war (Schmidt 2007). This letter, by disregarding existing law, enabled and empowered physicians to administer “a merciful death” (Lindert et al. 2012). The correspondence not only provided legal immunity to physicians and nurses, it served as the legal basis for the subsequent Nazi euthanasia program, Aktion T4. Of note, this letter is the only surviving document which clearly links Hitler to the killing program (Schmidt 2007).

5.6.2 Aktion T4

It is important to understand that no one was ordered to carry out these murders (Strous 2007). As Robert Proctor states, “In times of war or economic crisis things can happen that otherwise—in times of peace or economic stability—would never be tolerated” (Proctor 1999, 289). Hitler’s document not only provided legal protection, it also facilitated logistical collaboration between the medical profession and the government (Friedlander 1995). Even more importantly, it provided a mechanism to diffuse individual responsibility as Karl Brandt let his physician-colleagues know that in “Hitler’s name” they could carry out euthanasia (Schmidt 2007).

Hitler’s misdated correspondence disguised his intentions and shielded perpetrators during the initial phases of the invasion of Poland (i.e., formal beginning of World War II), when he believed citizens would otherwise be distracted and would have diminished concerns about the value of human life. This was “consciously thought” (Proctor 1992, 24) to be the “best time for the elimination of the incurably ill” (Lifton 2000, 50). War also allowed the implementation of more radical measures. Historians estimate 2000 Polish psychiatric patients were killed on September 22, 1939, at the Kocborowo (Conradstein) mental institution (Meyer-Lindenberg 1991; Lindert et al. 2012). By October 1939, the heads of all German psychiatric hospitals submitted forms identifying and “nominating” individuals with “hereditary” mental illness to an oversight committee of selected psychiatrists, eventually targeting an additional 70,000 patients for death (Torrey and Yolken 2010; Haque et al. 2012).

Between 1940–1945, a separate medical department within the Ministry of the Interior, located at Tiergartenstraße 4 (T4), supervised the registration of institutionalized patients as part of an economic planning registration. In a similar manner, the T4 consultants would determine whether transfers to specialized facilities were required.

What began earlier as the sporadic, incremental murder of disabled children, soon become the pilot program for Aktion T4, a centralized process of mass murder whereby selected victims were supposedly transported for “improved” treatment, but instead, were murdered at six dedicated killing centers based on geographical proximity: Brandenburg, Grafeneck, Hartheim, Pirna-Sonnenstein, Bernburg, and Hadamar (Strous 2007; Friedlander 1995; Grodin et al. 2018). Family members were not initially suspicious of these transfers because these facilities represented some of Germany’s most prestigious hospitals. Those who did try to intervene were considered “totally unreasonable” and admonished by the physician(s) (Friedlander 1995).

These euthanasia sites, however, were not chosen because of excellent specialty care, but because of their relatively isolated locations (Lifton 2000; Grodin et al. 2018). Brandenburg, for example, became the training ground for those who would implement the Reich’s child euthanasia program (Roder et al. 1994). These deaths generally occurred within the first twenty-four hours of the patient’s arrival (Lifton 2000). In many cases, the killing was done solely for the purpose of research. It wasn’t until 1990 that the stored brains of many of these victims were comprehensively identified when located in the “basement of the Max Planck Institute for Brain Research in Frankfurt” (Roder et al. 1994, 156). By 1945, there were around 5,000 “euthanasia” victims of this program (Longerich 2019).

Attempts to maintain the secrecy of this program failed, resulting in Hitler’s “official” discontinuation of the T-4 program on August 24, 1941, following increasing community protests from both the general population, the clergy and the legal profession (Ernst 2001; Lindert et al. 2012; Friedlander 1995). These protests notably included dissent from Catholic Bishop Clemens Graf von Galen in his famous August 4, 1941 sermon, and Brandenburg judge, Dr. Lothar Kreyssig (Longerich 2019; Friedlander 1995; Strous 2010). Kreyssig, a lower court judge in charge of guardianships, reported to the Reich Minister of Justice the disappearances and sudden deaths of his wards (Friedlander 1995).

After August 1941, the original killing centers on German soil were closed (Friedlander 1995). However, although the killing centers were shuttered, the killing did not stop. Medical personnel continued to carry out murders through an unofficial, decentralized process known as “wild euthanasia” (Lindert et al. 2012; Von Cranach 2003). In this “wild euthanasia” program, children and adults in the psychiatric hospitals and sanatoriums were killed with overdoses of sedatives or starvation, albeit more haphazardly (Lifton 2000). Further murders occurred in the concentration camps within occupied territories as part of the new program code-named, 14f13, which was initially intended to kill all handicapped and insane prisoners (Friedlander 1995; Lifton 2000; Grodin et al. 2018; Ernst 2001). If the SS camp physicians did not include a medical diagnosis within their documentation, the T4 physicians, now assisting in the camps, would. Operation 14f13 resulted in approximately 20,000 additional deaths. The T4 killings revealed that otherwise ordinary men and women were willing to participate in these murders. (Friedlander 1995). Without a firm ethical foundation, individuals felt that “they were doing (what) was correct from a moral and scientific standpoint; therefore, they were not the demons and ‘paradigms of evil’ that we perceive them to be” (Strous 2007, 4).

The German institutional physicians continued killing their patients until the target number of 70,000 was reached (Breggin 1993; Meyer 1988) thus providing a “rehearsal” (Proctor 1992, 24) for the subsequent genocide.

5.6.3 Mechanisms of Death

Again, it was the psychiatrists who were leading every step of these programs. Once the psychiatrists identified and certified which patients were to be transported to which destination, the psychiatrist used carbon monoxide, injections and starvation to facilitate their patient’s deaths (Bachrach 2004; Burleigh 1994; Strous 2007). Reprieve could only occur if the patient was a war veteran, a foreigner, or if the medical records were incomplete. Although medications could be used to kill handicapped children, different mechanisms were required to kill adults. Deception and subterfuge were essential in adult killing. Patients thought they were undergoing normal medical routines as they removed their clothing and entered the rooms disguised as showers (Friedlander 1995). Relatives and guardians were not notified until after transfer, “actually only after the patients were killed” (Friedlander 1995, 85). For those with unusual underlying illnesses, “(t)heir brains were immediately removed and dissected, many on the same day” (Roder et al. 1994, 156). Psychiatrists were also instrumental in certifying fraudulent death certificates purporting credible, natural deaths, which were sent to the next of kin by the “Condolence Letter Department” (Strous 2007; Friedlander 1995; Grodin et al. 2018; Lifton 2000). The police and local governments were no longer involved in the vital statistics record keeping of these facilities because the number of deaths would raise suspicions. Even the site of death was altered (Friedlander 1995).

By 1942, Ernst Rüdin “collaborated with leading figures of the euthanasia action to redefine the role of psychiatry in Germany. He declared his agreement, in principle, with the killing of the mentally handicapped” (Kuhl 2001, 186). Other psychiatrists, such as Kurt Pohlisch and Werner Villinger, served as medical experts in the handicapped and adult euthanasia programs. As Stefan Kuhl articulates, “killing was a neutral issue subordinated to the higher goal of race improvement” (Kuhl 2001, 204). As early as 1943, Hitler authorized the emergency transfer of psychiatric patients to other decentralized sites so that hospital beds could be made available near the war zones for those wounded in bombing raids (Longerich 2019; Pross and Aly 1991). The use of asylum beds for the hierarchical care and rehabilitation of war heroes camouflaged the murder of extant psychiatric patients.

Although there was now no formal approval from Hitler or the T4 administration, psychiatrists justified their continued participation in “euthanasia” activities based on eugenic principles. The decentralized nature of the killings redirected the program’s profile away from Hitler, while serving as a precursor to the Final Solution (Roder et al. 1994). With increasing experience in the murder of those deemed eugenically unfit, physicians abandoned their traditional ethical principles and expanded their killing net (Lifton 2000).

Lifton describe the perversion of the “healing-killing paradox” and how physicians rationalized these eugenic killings as a form of healing (Lifton 2000, 430–433). Omar Haque reiterates how physicians believed they were “saving the ones that most mattered amid the entire society” (Haque et al. 2012, 478). One observer noted “how rapidly gas caused death” (Friedlander 1995, 97), as if this made the process of killing humane. Karl Brandt confirmed the effectiveness of carbon monoxide as a “major leap …in medical history” (Schmidt 2007, 138). Another psychiatrist, Hermann Pfannmüller, the head of the Eglfing-Haar mental institution, remained deeply committed to a “Nazi worldview that demanded the elimination of…the pitiful patient who exhibited only the semblance of human existence” (Lifton 2000, 120). Pfannmüller, in his role as the director of this Reich Committee institution, developed policies of starvation instead of “wasting medications” on their deaths (Lifton 2000, 62). In contrast, the protests against this killing did not arise from within the medical profession, but rather from parents who protested against their “disappeared” children and from the churches, who believed in the sanctity of all human life (Lindert et al. 2012). Note, these stages of the genocide occurred prior to the Wannsee Conference held on January 20, 1942, which ratified “The Final Solution of the European Jewish Question” (Endlösung der europäischen Judenfrage) (Lindert et al. 2012).

At the camps, the “diagnosticians…according to Himmler’s wish, [were] experienced psychiatrists” (Ernst 2001, 4). The only physician to command an extermination camp who could be considered young (age 32), and “minimally trained”, was the psychiatrist Dr. Imfried Eberl (Strous 2010). His promotion was based on his acquired technical experience from Brandenburg and Bernburg, where he had previously coordinated the murder of “tens of thousands of mentally ill patients” (Strous 2010, 208; Strous 2007, 3) prior to becoming the commandant of Treblinka (Kaelber 2013, 22). It soon becomes apparent to the modern reader these expanded genocidal processes “would have been much harder to accomplish without the willing participation of physicians” (Grodin et al. 2018, 53).

5.6.4 Continued Psychiatric Leadership

On June 26, 1943, psychiatry’s “elite” (e.g., Rüdin, de Crinis, Carl Schneider, and Hans Heinze) wrote a memorandum about the future development of the field. This document described insulin, electro-convulsion and dietetic therapies and nominally characterized psychiatry as a healing discipline. However, the memorandum also emphasized that only the “economically valuable … (have) the right to live” (Roder et al. 1994, 183–184). In writing this paper, Rüdin complained about how psychiatry was getting a bad name because of the “completely wrong demands of the hereditarily sick” (Roder et al. 1994, 184). The psychiatrists neglected to mention, however, their role in genocide, or how, until Mengele, they were unable to “test psychiatric twin theories by comparing the side-by-side autopsies of twins” (Roder et al. 1994, 161). Even after the war, twin research continued at the German Research Institute for Psychiatry. Rudin’s daughter Edith performed schizophrenia research at the Max Planck Institute for Psychiatry and also minimized the “perceptions of her father’s role in the Third Reich” (Roder et al. 1994, 197).

In 1943, Rüdin further published: “It is the unfailing historical merit of Adolf Hitler and his true followers that they dared to take the first decisive step past the purely scientific discoveries to open the way for the ingenious racial hygienic work in and on the German people… [to] prevent the propagation of the hereditarily ill and inferior” (Roder et al. 1994, pp. 235–236).

The medicalized “euthanasia” program ultimately resulted in the deaths of an estimated eighty percent of the psychiatric patient population, “(a)pproximately 400,000 psychiatric and /or patients with disabilities” (Lindert et al. 2012, 7). After the war, the psychiatrist Fredric Wertham further described these activities: “The tragedy is that the psychiatrists did not have to have an order. They acted on their own” (Wertham 1966, 161; italics added). Contrary to what many people continue to believe, there was no coercion. There were no mandates. There were only choices made to kill those deemed unfit by those entrusted to heal and care.

5.7 Resistance

Although psychiatrists were not the only physicians involved in genocide, their willing participation justified by the premise of eugenics facilitated the planning and implementation of involuntary sterilization and euthanasia (Strous 2007). “Young doctors, who were the most innovative and enthusiastic…may have been easily convinced to accept and participate or excuse the killing of the non-curable ill…as an inevitable professional part of healing the curable” (Lindert et al. 2012, 9–10). Psychiatrists could no longer claim the professional mantle and privilege of a moral agent. When their patients became re-defined as “useless eaters,” they took a critical step along the slippery slope of criminal genocide. According to Rael Strous and Johannes Meyer-Lindenberg, very few psychiatrists publicly protested against these injustices. There were some notable examples, however, including: Martin Hohl, Hans Cruetzfeldt, Gottfried Ewald and Karsten Jasperson (Meyer-Lindenberg 1991). Dr. Jasperson, although a member of the National Socialist party (1933), was the head of the Department of Psychiatry at Bethel and wrote a memorandum to Hitler protesting the institutional registration forms in 1940 which identified patients for transfer (Ernst 2001). Jasperson also alerted Cardinal von Galen, who openly condemned these murders during his famous sermon in Lambert church (Meyer-Lindenberg 1991). Another opponent of National Socialism, Dr. John Karl Friedrich Rittmeister, was ultimately arrested and tortured by the Gestapo prior to his death by guillotine on May 13, 1944, in the Berlin-Plötzensee prison (Ernst 2001). In 1942, Professor Jurg Zutt, the editor-psychiatrist for the journal Zentralblatt für die gesamte Neurologie und Psychiatrie opposed the “great injustices” associated with psychiatric advocacy surrounding determinations of inferiority and genetic/mental illness (Roder et al. 1994). None of the protesting psychiatrists were able to prevail against the power psychiatry wielded in the Third Reich. Dr. Cruetzfeldt, who managed to save the majority of his patients, was only able to bring Werner Hyde, the Wurzburg Chair in Psychiatry and T4 Medical Director, to justice after the war (Lifton 2000; Lindert et al. 2012; Meyer-Lindenberg 1991).

Another example of resistance within the medical community was the White Rose (Die Weibe Rose), a non-violent, opposition group founded by five medical students from the University of Munich in 1942 (Lindert et al. 2012). Two members, brother and sister Hans and Sophie Scholl, were caught distributing leaflets denouncing the Nazi regimen on February 18, 1943, along with Christoph Probst. All three were tried on February 22, 1943 and executed by guillotine that same day (Ernst 2001). They were not given an opportunity to speak in their defense. Although most Germans accepted some level of Nazi ideology, the swift and immediate actions taken by the Nazis to silence any type of opposition or resistance demonstrates the “depth of their commitment and the degree of their radicalism” (Friedlander, 197).

5.8 Summary

Alexander Mitscherlich (1908–1982), a neurologist/psychoanalyst, and his co-author, Fred Mielke, were chosen as the delegates of German medicine to attend the Nuremberg Medical Trial (Hirsh 1949). Their seminal 1947 book Doctors of Infamy describes how eugenics, eugenicists, psychiatrists and the psychiatric euthanasia programs were instrumental in the eventual development of the Holocaust:

This became the starting point for a line of development that inexorably led to enforced ‘mercy death’ for the incurably insane on the one hand, and, during the war, on the other, to plans for exterminating races declared to be inferior (Mitscherlich and Mielke 1949, 90).

Their book describes how doctors could become licensed killers. Physicians’ belief in the truth of eugenics in combination with the ideology of National Socialism led to the degradation of the medical profession. As racial hygiene became ingrained within medicine and politics and as more people were classified as “unfit,” the progressive, systematic processes of dehumanization and medicalization became routine, and served as a mechanism to reinforce already existing prejudices and biases. As the evidence of war crimes became apparent to the Allied forces, criminal trials were the mechanism to illuminate and immortalize the evidence. The legal system (vis-à-vis the Doctors’ Trial) became one such mechanism to correct the misconduct. Even though the victims did not receive complete justice, the Doctors’ Trial resulted in the creation of the Nuremberg Code, a set of ten principles of ethical conduct that were intended to guide international human subject research and ensure that this misconduct of this magnitude was never repeated. The rate of suicides among Nazi physicians after the German defeat escalated and included Max de Crinis (May 2, 1945), and several other senior SS officials within custody who had access to cyanide (Schmidt 2007). Even the Führer’s personal bunker surgeon, Ludwig Stumpfegger, provided the cyanide used in the deaths of Hitler, Eva Braun, Hitler’s dog Max, and Magda Goebbels’ six children (History Collection). Dr. Eberl committed suicide in 1948 while awaiting trial (Kaelber 2013).

As Jutta Lindert describes: “…the leading psychiatrists of the time…voluntarily and often enthusiastically took part in all stages of the operation to kill their defenseless victims. But…when confronted after the war with their deeds, denied any knowledge or responsibility” (Lindert et al. 2012, 16). Otherwise, they would have had to acknowledge that their participation was amoral and not permissible. Their loyalty to the Volk replaced the normative values and moral compass which were central to the physician–patient relationship.

Peter Breggin further chronicles the range of psychiatric involvement which began with the development of eugenic philosophy, followed by Binding and Hoche’s (1920) book justifying “mercy killing,” through physicians’ integration of extermination programs within state mental hospitals, their subsequent technological education and staffing of the extermination camps, and their direct involvement in the murder of millions (Breggin 1993).

In closing, the field of psychiatry provided the scientific justifications and the mechanisms for practically implementing the eugenically-based sterilizations, child euthanasia, Aktion T4 and the later Operation 14f13 programs. Psychiatrists exterminated an estimated 220,000 and 269,500 German individuals with schizophrenia (Torrey and Yolken 2010). Other estimates by Fredric Wertham suggest the total number of killed psychiatric patients may have been as high as 275,000. It is important to understand that Nazi genocide was based on erroneous Mendelian genetic theories and “was the greatest criminal act in the history of psychiatry” (Torrey and Yolken 2010, 26).

By becoming an instrument of genocide on behalf of the state, psychiatrists were no longer constrained by their personal or professional moral codes. Their methods for treating and preventing mental illness and protecting the public’s health were eugenic sterilization and genocide. Their willingness to place a value on human life determining who would live and who would die is contrary to the foundational principles of medicine. While psychiatrists stand out among medical professionals due to their ability to conflate clinical diagnoses with the worth of an individual, the direct and systematic involvement of the entire medical community in the labeling, persecution, sterilization and mass murder of millions of people deemed “unfit” based on the very criteria they defined, stands as the most egregious abuse of the power of science and medicine in modern history. Contemporaneous understanding of the process by which healers became killers and our moral responsibility to all members of society, will help ensure that this never occurs again.