The powers of suggestion: Albert Moll and the debate on hypnosis

The Berlin physician Albert Moll (1862–1939) was an advocate of hypnotic suggestion therapy and a prolific contributor to the medical, legal and public discussions on hypnotism from the 1880s to the 1920s. While his work in other areas, such as sexology, medical ethics and parapsychology, has recently attracted scholarly attention, this paper for the first time comprehensively examines Moll’s numerous publications on hypnotism and places them in their contemporary context. It covers controversies over the therapeutic application of hypnosis, the reception of Moll’s monograph Der Hypnotismus (1889), his research on the rapport between hypnotizer and subject, his role as an expert on ‘hypnotic crime’, and his views on the historical influence of hypnotism on the development of psychotherapy. My findings suggest that Moll rose to prominence due to the strong late-nineteenth-century public and medical interest in the phenomena of hypnosis, but that his work was soon overshadowed by new, non-hypnotic psychotherapeutic approaches, particularly Freud’s psychoanalysis.


Introduction
Hypnosis was a controversial topic of medical, legal and public debate in several European countries during the late nineteenth and early twentieth centuries. The therapeutic potential of hypnotic suggestion was balanced against the dangers of a mental state that made the individual a powerless subject of the hypnotizer's will and commands. The risks of induced nervousness and hysterical fits, of sexual abuse of hypnotized persons, and of criminal suggestions were invoked when treatment with hypnosis was discussed (Chettiar, 2012;Gauld 1992;Wolf-Braun, 2000;Wolffram, 2009: 83-130). Moreover, in the eyes of its critics, medical hypnosis had uncomfortable resemblances or links with the mesmeric or 'magnetic' treatments by lay healers, the stage performances of lay hypnotists and female 'trance-dancers', as well as the trance states of spiritualist mediums in occult séances (Hales, 2010;Kennaway, 2012;Teichler, 2002;. In addition, simulation by patients or test persons was seen as a problem in assessing the efficacy of hypnotic interventions (Bugmann, 2012: 60-4). The Berlin physician Albert Moll (1862Moll ( -1939 was a key participant in these debates and established himself as an expert in hypnosis and suggestion therapy (Cario, 1999;Hahn and Schröder, 1989;Wendelborn, 1994;Winkelmann, 1965). Heather Wolffram in particular has recently considered his role in the efforts of a group of physicians in Imperial Germany to legitimize medical hypnosis as a therapeutic method and to demarcate it from contemporary research into paranormal, occult phenomena .
However, while Moll's expertise in other areas, particularly in sexual science, medical ethics and parapsychology, has recently been discussed in detail, we still lack a fuller account and analysis of his numerous contributions to the debate on hypnosis. Recent historical research has emphasized his innovative work on a theory of the human sexual drive and of childhood sexuality, his conceptualization of a contract-based ethics of the doctor-patient relationship, and his scientific and polemic critiques of occultism (Maehle and Sauerteig, 2012). However, how significant was Moll's engagement, in theory and practice, with the method of hypnosis? As Sonu Shamdasani (2005: 4-5) has shown, the notion of 'psychotherapy' or 'psycho-therapeutics' emerged in the late nineteenth century in the context of the hypnotic movement; so much so, that 'psycho-therapeutics' and 'hypnotic suggestion' were initially used synonymously. How did Moll view the development of 'modern' psychotherapy, including the rise of psychoanalysis?
This paper examines Moll's role in the contemporary discourse on hypnosis (or 'hypnotism', as it was often called). It considers his efforts to establish hypnotic suggestion as a therapeutic method, the reception of his successful textbook on hypnotism, his experimental research on the rapport between hypnotizer and subject, his comments and expert statements in the field of 'hypnotic crime', and his assessment of the legacy of hypnotism for the development of psychotherapy. My findings suggest that Moll rose to prominence in the context of the medical and public interest in hypnotism in the late nineteenth century, becoming accepted as an authority in this field, but that his work was soon overshadowed by newer, non-hypnotic psychotherapeutic approaches, in particular Freud's psychoanalytic method.

Controversy over the therapeutic use of hypnosis
After passing his medical exams at Berlin University in 1884 and his promotion to MD in the following year, Albert Moll visited the clinics of Vienna, Budapest, London, Paris and Nancy before he opened a private practice for nervous diseases in 1887 in Berlin (Moll, 1936: 20-30). In a session of the Berlin Medical Society (Berliner medizinische Gesellschaft) on 26 October 1887, chaired by Rudolf Virchow , the 25-year-old Moll reported on what he had learned about hypnosis during the 4 months he spent with the neurologists Jean-Martin Charcot  and Joseph Babinski (1857Babinski ( -1932 at the Salpêtrière hospital in Paris, as well as during his visits to the Professor of Internal Medicine Hippolyte Bernheim  at the University of Nancy and the psychiatrist Daniel Hack Tuke (1827-1896) in London. In hysteric patients at the Salpêtrière, Moll had seen Charcot's classic three stages of hypnosis -lethargy, catalepsy, and somnambulism -but he could not rule out the possibility that these states were merely artificially produced by suggestion. Moreover, he was not convinced of the close link between hypnosis and hysteria that Charcot and his followers assumed. Charcot's school regarded hypnosis as an abnormal physical state of the nervous system (Gauld, 1992: 311). Moll, in contrast, was inclined towards the view of Bernheim, the physician Ambroise-Auguste Liébeault (1823Liébeault ( -1904 and others of the so-called Nancy School (Janet, 1925, 1: 172-80;Gauld, 1992: 319-27) that hypnosis was a purely psychological phenomenon which was caused by suggestion. Drawing upon his experience with hypnosis in France, especially in Bernheim's clinic, and some trials on his own patients in Berlin, Moll argued that hypnotizing patients and then suggesting to them improvement or disappearance of their symptoms was a successful method of treatment in a number of conditions, such as cases of neuralgia, agitated states of neurasthenia, sleeplessness and headaches. Most cases in which Moll had seen improvements after hypnotic suggestion therapy were 'functional' disorders, as he admitted, but he also claimed to have used it to remove the joint pains of a patient with rheumatism, and referred to Hack Tuke in support of the possibility that other somatic diseases might be positively influenced by this method as well. On this basis, Moll (1887) called for further 'objective observation' of hypnotic treatment; if qualified doctors would not address this matter, he warned, lay 'magnetizers' and 'somnambulists' might dominate this field 'in their way'.
Moll's 1887 paper provoked critical reactions by some established members of the Berlin Medical Society during its discussion in the next session, on 2 November 1887. The internist Karl Anton Ewald (1845Ewald ( -1915, who had also witnessed Charcot's demonstrations of hypnosis on hysterics at the Salpêtrière and who had made largely unsuccessful hypnotic trials in the Berlin Women's Infirmary (Frauensiechenanstalt), reported that he had allowed Moll to hypnotize two of his patients who suffered from hysterical complaints. Like Ewald, Moll had failed to produce any deeper hypnotic state in them (Ewald, 1887). While Ewald accepted that suggestion played a role in daily life, he saw no benefit of it for medical treatment, particularly not in hysteric patients who were known for 'wanting to have their way'. The high suggestibility that Moll had seen in Nancy was for Ewald a kind of psychic epidemic in a small provincial town. With forceful words Ewald protested against Moll's use of the term 'medical treatment' for hypnosis and suggestion: something that 'every shepherd, shoemaker and tailor' could achieve, if he only had the necessary selfconfidence, did not merit the name of a medical therapy. According to Ewald, hypnotic suggestion was just a 'trial' or 'experiment' that one might make in clinical settings to study the extent of psychophysical influences on an individual, but not a method of treatment by doctors (Ewald, 1887).
Strong criticism came also from the Berlin Professor of Psychiatry, Neurology and Forensic Medicine, Emanuel Mendel (1839Mendel ( -1907 (Fleckner, 1994). As another witness of Charcot's demonstrations he was convinced that the latter's patients had been 'prepared' and trained. Mendel (1887) sharply rejected Moll's claim that hypnosis and suggestion were harmless means of treatment. From his experience Mendel warned that continued hypnotizing caused nervousness in the subjects and made nervous patients 'even more nervous'. Only in carefully selected cases of hysteria or neurasthenia might hypnotic suggestion be cautiously tried as a method of last resort. In any case, improvements of the patient's state were likely to be only temporary (Mendel, 1887). Mendel's warnings were endorsed by the Berlin psychiatrist Carl Moeli (1849Moeli ( -1919, who reported that he had seen how hypnosis triggered hysteric fits and convulsions in some patients (Moeli, 1887).
Moll was not disheartened, however, by these critical reactions. To the contrary, he started a kind of campaign for hypnotic treatment, regularly inviting medical colleagues to his home and demonstrating the effects of hypnosis to them (Moll, 1936: 33). Outside the medical professional circles, he soon found a congenial environment in the Berlin Society for Experimental Psychology (Gesellschaft für Experimental-Psychologie), which had been founded in early 1888 by a diverse group of intellectuals interested in hypnosis and in occult phenomena. The group included the young Berlin philosopher Max Dessoir (1867Dessoir ( -1947, the art historian Friedrich Karl von Goeler-Ravensburg (1854-96), the writer Otto von Leixner (1847Leixner ( -1907, and the former colonial director in Brazil and spiritualist Albrecht Wilhelm Sellin (1841Sellin ( -1933. Moll soon established himself in this society as one of its most active members (Dessoir, 1947: 126-9;Kurzweg, 1976;Wolffram, 2009: 35-6). Dessoir, who became a friend of Moll, published a bibliography of the international literature on hypnosis, suggestion and related topics, which included over 800 titles (Dessoir, 1888). In July 1888 the Munich physician Albert von Schrenck-Notzing (1862-1929, who later became a key figure in German parapsychology (Sommer, 2012;Wolffram, 2009), presented his inaugural dissertation on the therapeutic use of hypnosis, with an international overview and including an account of his own trials. He mentioned that he had visited Moll in Berlin in the previous April, and each day watched Moll's trials with suggestion therapy, and reported that this method had been successfully applied in cases of 'hysteric aphonia, hysteric clavus, ovarian pain, cardialgia, athetosis, neurasthenia, psychic impotence, pruritus cutaneus nervosus etc' (Schrenck-Notzing, 1888: 53).
August Forel (1848Forel ( -1931, the Director of the Burghölzli Asylum and Professor of Psychiatry in Zurich, who had visited Bernheim in 1887, became an important ally of Moll, defending him against Ewald's criticism. As Forel (1889: 11) bluntly put it: 'If only this shepherd's therapy works, that's the main point!' By this time, Forel had tried hypnosis on over 200 persons, partly healthy subjects such as the asylum staff, partly mentally ill patients. He confirmed that hypnotic suggestion could influence menstruation, remove headaches and induce insensibility so that small operations could be performed without pain (Forel, 1889: 11, 26-7; see also Bugmann, 2012). Moreover, the Professor of Psychiatry and Neurology at the University of Graz, Richard von Krafft-Ebing (1840, who had extensively studied -from October 1887 to June 1888 -the hypnotic phenomena in a highly suggestible, female hysteric patient of his clinic (Oosterhuis, 2000: 121-3), concluded: 'I regard hypnotic suggestion as a valuable addition to the therapy of functional nervous diseases.' (Krafft-Ebing, 1889: 87). In Vienna, the physiologist and neuro-anatomist Heinrich Obersteiner , whom Moll had visited on his 'grand tour', saw three 'directions' in which hypnotism could become therapeutically effective: through the state of hypnosis itself, through causing anaesthesia and, most importantly, through suggestion. Like Krafft-Ebing, he expected hypnotic suggestion to be particularly useful in the treatment of 'functional neuroses', especially hysteria (Obersteiner, 1887: 70-4).
On 10 April 1889 Moll reported on his further therapeutic experiences to the Berlin Medical Society. By then he had treated about 120 patients with hypnosis. The main topic of his presentation was the responsiveness of hysteria to hypnotic suggestion. On the basis of his cases of female and male hysteric patients, Moll felt that those who displayed a multitude of often changing symptoms were difficult to treat in this way, whereas he had successes in patients who had only one or several constantly occurring symptoms (Moll, 1889a). In the subsequent discussion, however, Ewald (1889) maintained his view that hypnosis, lacking precise indications and being dependent on the patient's will, could not be viewed as a medical treatment in the strict sense but belonged to the field of psychology. Also Mendel (1889) commented again, highlighting problems such as the induction of hysteric fits and, after repeated hypnoses, a kind of craving for being hypnotized that he compared with morphine and alcohol addiction. In his final statement, Moll (1889b) insistedunlike Ewald -that psychology should be applied in medicine, in the same way as physics was applied in electrotherapy and chemistry in drug treatments.
Moll's experience at the Berlin Medical Society reflected the considerable resistance in the medical profession to a method that did not easily fit with the prevailing materialist scientific paradigm. Moreover, due to its historical roots in mesmerism, hypnosis carried for many the hallmarks of charlatanry, regardless of the support from prominent members of the psychiatric profession such as Krafft-Ebing and Forel (Teichler, 2002). In the German context, the fact that much of what was known about hypnosis came from France (the former national enemy and scientific and cultural rival) is likely to have influenced debates as well. This is suggested, for example, by the scepticism that was repeatedly expressed regarding Charcot's demonstrations on hysterics. Moll, however, does not seem to have been much influenced by these views, perhaps due to his independence as a doctor in private practice and a more international perspective, linked to his Jewish background. In fact, he later argued against 'scientific chauvinism', using the example of an unnamed German researcher who had rejected hypnotism 'like an epidemic brought in from France' (Moll, 1902a: 577). In any case, his papers on therapeutic hypnosis made Moll's name widely known in the medical profession, as they were reported not only in the proceedings (Verhandlungen) of the Berlin Medical Society, but also in Germany's most important medical weeklies, the Deutsche Medicinische Wochenschrift, the Berliner Klinische Wochenschrift and the Münchener Medicinische Wochenschrift. 1 By April 1889 Moll had written a textbook on hypnosis which was going to become an international success.

Moll's book Der Hypnotismus
In less than 300 pages Moll's monograph Der Hypnotismus gives an overview of: the historical development of hypnosis; its physiological and psychological symptoms; its current theoretical explanations; the problem of simulation by subjects or patients; cognate states such as sleep and suggestion in the waking state; medical applications of hypnotic suggestion; forensic issues linked with hypnosis; and controversial phenomena such as animal magnetism, telepathy and clairvoyance (Moll, 1889c). As he acknowledges in the preface, Forel had allowed him to use some of the hypnotic trials that had been made in the Burghölzli Asylum, and Dessoir had helped Moll with his detailed knowledge of the literature on hypnotism. In addition, Moll draws on his own experiments with hypnosis (Moll, 1889c: iii). Theoretically, he mainly follows the line of the Nancy School that hypnosis is a psychological state caused by suggestion. Moreover, the individual's own ideas are somehow inhibited during hypnosis, according to Moll, a view which he attributes to the Breslau Professor of Physiology, Rudolf Heidenhain (1834-97), who had experimented with hypnosis around 1880 and characterized the hypnotic state as an inhibition of the cells of the cerebral cortex (Moll, 1889c: 152-4; see also Gauld, 1992: 303-5). Moll is also inclined to understand hypnosis psychologically as a change in a person's attention, in agreement with the influential Leipzig experimental psychologist, Wilhelm Wundt (1832Wundt ( -1920 (Moll, 1889c: 155;Wundt 1911). Regarding the use of hypnotic suggestion as a medical therapy, Moll (1889c: 212-15) asserts, in opposition to Mendel's warnings, that he does not know of any contraindication.
Reviews of Moll's book in the German medical press were on the whole appreciative, but included also a number of criticisms. Both the reviewer for the Münchener Medicinische Wochenschrift, the Swiss psychiatrist Eugen Bleuler (1857-1939) (Bleuler, 1889), and the anonymous reviewer for the Berliner Klinische Wochenschrift welcomed it as the first larger German work on hypnosis (Anon., 1889). Opinions were divided, however, whether Moll's approach to write in a manner that was accessible to non-medical as well as medical readers was justified or even successful. While the latter reviewer thought that this approach had done 'no harm' to the book, Bleuler believed that it was a disadvantage, because in a topic as controversial among experts as hypnosis it would just create confusion in the wider public. The reviewer for the Deutsche Medicinische Wochenschrift, the Halle Professor of Neurology, Adolph Seeligmüller , feared that regardless of Moll's explanations much would remain 'dark and incomprehensible' for non-medics and he felt that Moll's treatment of the subject matter was rather uneven, although he acknowledged that the latter had taken a critical perspective in writing the book (Seeligmüller, 1889).
A generally positive review was published in the Journal of Mental Science by the English physician Arthur T. Myers (1851-93), a brother of the psychical researcher Frederic W.H. Myers  and like the latter a member of the London Society for Psychical Research (Gauld, 1992: 390). This review concluded with the recommendation to translate Moll's book into English (Myers, 1889). In fact, in the following year, 1890, an English version was published in the Contemporary Science Series edited by the sexologist Havelock Ellis ; it was based on the second German edition, which Moll had completed in January 1890. While he had taken into account some of the criticisms in his revisions, he had refused to rewrite the book for physicians only. As he explained in the preface to the second edition, he believed 'that hypnotism is a province of psychology, and is in consequence of as much interest to psychologists and lawyers as to doctors' (Moll, 1891: xi). The first English version was reviewed in Nature (again by A.T. Myers, 1890), Science, and Mind as well as in the Lancet and the British Medical Journal. Besides the comprehensiveness of Moll's account, the reviews in the first three journals emphasized the 'non-combative', 'cautious and judicious' and 'soberly thought-out' character of his discussion, which was welcomed in view of the contemporary strong public interest in hypnosis and other unusual mental phenomena (Anon., 1890a; Anon., 1890b; Myers, 1890). Paying more attention to the therapeutic side of hypnosis, the reviews in the medical journals echoed the above-mentioned general assessment of Moll's book (Anon., 1891a; Anon., 1891b). A second English edition was published by 1891.
The immediate success of Moll's book on hypnosis reflected, apart from its own merits, the generally strong medical, scientific and public interest in the topic during the years around 1890, which have been called the 'golden age' of hypnotism (Gauld, 1992: 578;Teichler, 2002: 37). The English translation appeared at a time when British physicians, like their German colleagues, controversially discussed whether hypnosis should be adopted as a legitimate therapy in professional medical practice (Chettiar, 2012). Moll's book continued to be in demand, reaching the status of a standard text. A third, augmented German edition appeared in 1895, a fourth in 1907, and a fifth in 1924 (Moll, 1895(Moll, , 1907a. 2 By this last edition the text had grown to over 700 pages. Moll's additions were particularly due to his developing interest in psychotherapy more generally (see below) as well as his increasingly critical attitude towards occultism and parapsychology (Sommer, 2012;Wolffram, 2012b). In the meantime, however, Moll had done an extensive series of experiments on a key aspect of hypnosis: the 'rapport' or special psychological relationship between hypnotizer and subject, which he discussed in a separate monograph (Moll, 1892).

Experimentation on hypnotic rapport and the concept of the 'double-ego'
At the end of his historical overview in Der Hypnotismus, Moll had mentioned that followers of Franz Anton Mesmer (1734-1815) still existed and could be seen as a third school besides those of the Salpêtrière and of Nancy (Moll, 1889c: 10). It was against these mesmerists that Moll wrote his detailed study of hypnotic rapport. A central tenet of mesmerism was that the rapport between experimenter and subject was caused by a 'magnetic fluidum', i.e. a specific physical force, which the former transferred to the latter (Crabtree, 1993;Gauld, 1992;Schott, 1985). However, in the early nineteenth century these 'fluidists' had already been challenged by the so-called 'animists' who held that the magnetizer's influence was a mental or moral one (Janet, 1925, 1: 159-61). Moll's experiments, which aimed to show that the rapport, like hypnosis more generally, was a purely psychological phenomenon produced by suggestion, stood in a tradition of 'animist' critiques of mesmerism. His trials were performed with other members of the Berlin Society for Experimental Psychology, especially with Max Dessoir, A.W. Sellin, who had a reputation for 'owning the mysterious power of animal magnetism' (Moll, 1936: 129), and the jurist Adolf von Bentivegni, who had studied the significance of hypnosis for civil law (Bentivegni, 1890). The identity of the subjects was not revealed in Moll's account -they were referred to anonymously as X, Y and Z, although Moll emphasized that the experiments had been carried out on more than three individuals (Moll, 1892: 3).
The subjects were hypnotized through mesmeric passes, visual fixation of objects or verbal suggestion, and the so-called isolated rapport was ascertained by showing that the subject followed only the hypnotizer's commands or suggestions. Moll then varied the experimental conditions, demonstrating that through certain verbal interventions or by touching the subject, a further experimenter could enter the existing rapport, making the subject also respond to his suggestions, or even altogether transfer the rapport to himself. For Moll, this indicated that the rapport was not caused by some specific physical power of the hypnotizer, such as the 'animal magnetism' of the mesmerists, but had to be explained psychologically (Moll, 1892: 72-4, 91, 103, 111, 222-3). Sellin (1920: 95), mentioning the experiments in his memoirs, admitted that they convinced him to modify significantly his former mesmerist beliefs. Moll (1892: 119-20, 128-9) compared the hypnotic rapport with other psychological phenomena such as strong trust between doctor and patient, or belief in authority figures or experts. More specifically, he interpreted his experimental findings by using Dessoir's concept of the 'doubleego' (Doppel-Ich). According to Dessoir (1890), the human personality consisted of at least two spheres, the conscious Oberbewußtsein ('upper consciousness') and the usually hidden Unterbewußtsein ('subconsciousness'). For him, hypnosis consisted of creating an artificial preponderance of the latter, which he also called 'the secondary ego'. As he further explained: 'The key point of all methods of hypnotizing would then be to awaken the subconsciousness, to do in a planned and artificial way what in the life of the healthy and ill human being nature shows us in its first outlines and its highest formation.' (Dessoir, 1890: 27). The hypnotic or somnambulist state, with the 'subconsciousness' brought into the foreground, was characterized, according to , by intactness of most psychic faculties, but also a childish credulity, a tendency to translate everything into direct sensual experience, a change in active attention, and difficulties in producing inhibitory ideas.
Moll (1892) applied Dessoir's concept in proposing that in the state of so-called isolated rapport everything that the hypnotizer said to the subject was entering the latter's consciousness. When a second experimenter started speaking to the hypnotized person, this would be perceived only by the person's 'subconsciousness'. If the first experimenter (i.e. the hypnotizer) then made the subject -through suggestion or in other ways -remember what the second experimenter had said, he caused the relevant ideas to move from the subject's 'subconsciousness' to the subject's 'upper consciousness'. For Moll, this explained how the hypnotic rapport between hypnotist and the subject could be entered by, or even be transferred to, a third person. It also explained for him why subjects when woken up from the hypnotic state often could not remember what had happened during the hypnosis but did remember these things after they had been hypnotized a second time. 'Upper consciousness' and 'subconsciousness' were not always strictly separated, but ideas could move from the latter to the former and vice versa (Moll, 1892: 223-4). That the subjects had subconsciously perceived certain events during the hypnotic state could also subsequently be shown by 'automatic writing', i.e. by letting them write on a piece of paper while their active attention was absorbed by other matters, for example by a conversation (Dessoir, 1890: 21-2;Moll, 1891: 246-8;Moll, 1892: 224).
Dessoir's theory of the 'double-ego', which had been inspired by Pierre Janet's (1859-1947) work on psychological automatism (Dessoir, 1890;Janet, 1889; see also Crabtree, 1993: 307-26), made its author well known in the field of hypnotism and beyond (Dessoir, 1947: 38;Ellenberger, 2005: 214;Gauld, 1992: 389). Moll's allegiance with Dessoir, in theoretical interpretation as well as in experimental practice, may have given further intellectual weight to his work on hypnosis and his attempts to win support for the use of hypnotic suggestion as a respectable method of medical treatment. In fact, Moll's 1892 monograph on the hypnotic rapport received favourable reviews by Friedrich Umpfenbach , senior physician in the psychiatric clinic of the University of Bonn, and by the physician Jonas Grossmann (1856Grossmann ( -1930 who together with Forel had founded in 1892 the Zeitschrift für Hypnotismus, of which Moll, Dessoir, Freud, Schrenck-Notzing, Bernheim, Liébeault and several others were co-editors (Grossmann, 1892/93;Tanner, 2003;Umpfenbach, 1893). However, the doyen of academic experimental psychology, Wilhelm Wundt, who otherwise acknowledged Moll's scientific approach to the topic of hypnosis, took a dim view of the theoretical aspect of the latter's work. For Wundt (1911), Dessoir's distinctions of subconscious and conscious states were just introductions of terminology that did little actually to explain the phenomena of hypnosis and suggestion. Moreover, he disliked the resemblance of Dessoir's concept of the 'second ego' to notions of occultism, such as 'the second face' of a person, or with ancient beliefs in demonic possession. Wundt (1911: 24-7) regretted that Moll had adopted Dessoir's theory of the double-ego. It is thus debatable whether Moll's links to Dessoir and the lay-dominated Berlin Society for Experimental Psychology with their interest in occult phenomena did, in the end, enhance his scientific reputation. In fact, as Dessoir (1947: 127) recalled in his memoirs, in Berlin some academics rejected the Society for Experimental Psychology and formed a separate society named Hirnrinde (i.e. cerebral cortex).
However, Moll continued to adhere to the concept of subconscious mental spheres. This became manifest, for example, in the political weekly Die Zukunft, when he defended a new series of hypnotic experiments by Krafft-Ebing against its critics (Moll, 1893). Krafft-Ebing, who was Professor of Psychiatry in Vienna at that time, had repeatedly hypnotized a 33-year-old voluntary subject, Clementine Piegl, and claimed to have put her, through hypnotic suggestion, back into phases of her childhood and youth. Miss Piegl had acted in these states in a childlike, age-appropriate fashion, and handwriting samples then given by her resembled those that had survived from her youth. Krafft-Ebing (1926) believed he had actually reactivated forgotten and subconscious states of mind in her rather than just made her perform types of behaviour at a certain age. In one experiment, when it had been suggested to Miss Piegl that she was seven years old, she was suddenly shown her mother. Although she recognized her, she said that her mother looked so different, and she became frightened and started to cry in a childlike manner (Krafft-Ebing, 1926: 15-16). Both Krafft-Ebing (1926: 36) and Moll (1893: 503) regarded this as a key experiment indicating that the subject had in fact been placed in an earlier stage of consciousness.
Critics, however, suspected fraud by the subject. After Krafft-Ebing had demonstrated his experiments on Piegl at a meeting of the Vienna Society for Psychiatry and Neurology in June 1893, the neurologist Moritz Benedikt (1835-1920) ridiculed him in the daily press for having been duped by a hysteric woman (Krafft-Ebing, 1926: 30-1;Oosterhuis, 2000: 123). Moll's public defence of Krafft-Ebing and his subject was largely a scathing critique of Benedikt, whose credibility he tried to undermine in turn. Benedikt, Moll (1893: 501) claimed, was a notorious habitual opponent and prone to autosuggestion when it came to the success of his own treatments. Moll had now fully entered the public debate on hypnotism and mental illness.

Moral dangers and hypnotic crime
Unsurprisingly therefore Moll also commented on the topic of public stage performances by lay hypnotists. In Prussia these public performances had been forbidden by the police in 1881, following a ministerial decree that had characterized them as physiological experiments which might have harmful effects on the health of the subjects (Teichler, 2002: 189-90). Since then, however, this ban had been circumvented by holding hypnotic demonstrations at meetings of societies, so that they were formally non-public events and thus did not allow the police to intervene. Moll (1894) questioned whether these society meetings were strictly non-public in the legal sense if members could bring (paying) guests or if anyone could become a member for a small fee. Therefore, in his view, the police could and should intervene. Generally, he regarded demonstrations of hypnosis in public as unethical because they violated the subjects' human dignity, even if they were volunteers. While Moll's comments on this issue may well be seen as a professionally motivated move to demarcate legitimate medical hypnotism from the activities of lay hypnotists and 'magnetic' healers, 3 they also reflected wider concerns in contemporary society about the moral dangers of hypnosis. A major topic of debate was the possibility of hypnotic crime -a theme to which Moll made several contributions. Besides the risk that hypnotized subjects could become victims of sexual assault by the hypnotizer, there was speculation that an individual might be induced to commit a crime, either in a state of hypnosis or as a result of post-hypnotic suggestion (Gauld, 1992: 494-503). In Der Hypnotismus Moll (1889c) referred to some, predominantly French legal cases concerning rape of hypnotized patients or subjects and argued that in the German context such cases would be punishable under sections 176-178 of the German Penal Code (Strafgesetzbuch), which covered rape of 'unconscious', 'weak-willed' (willenlose), or mentally ill women (pp. 228-30). Criminal acts committed by a hypnotized subject, during hypnosis or afterwards due to posthypnotic suggestion, could on the other hand be exempt from punishment under sections 51 and 52 of the Penal Code, as they were acts committed in a state of 'unconsciousness' or mental disturbance with a lack of free will, or under irresistible coercion (pp. 232-6). A similar position regarding the lack of responsibility of the hypnotized individual had been taken in a study of hypnosis and crime by the Zurich Professor of Law, Karl von Lilienthal (1853 (Lilienthal, 1887: 386). Also, Obersteiner (1887: 77) had expressed the view that persons in a state of hypnosis or implementing a post-hypnotic suggestion were not responsible for their actions, as their own will was entirely subjected to that of the hypnotizer. In recognizing the possibility in principle that a person could be made to commit a crime through hypnotic suggestion, Moll was in agreement with the Nancy School, in particular with the Professor of Law, Jules Liégeois (1823-1908), and Liébeault who had 'successfully' experimented regarding this question (Gauld, 1992: 499-500;Liébeault, 1894/95).  claimed, for example, to have induced one of his patients through post-hypnotic suggestion to commit a theft in the home of another patient and shortly afterwards to return the stolen objects.
The themes of hypnotic crime and the 'double-ego' merged in the realm of fiction. In 1893 the writer Paul Lindau (1839-1919), who was personally acquainted with Dessoir and Moll (Dessoir, 1947: 235-7;Moll, 1936: 85), published his stage play Der Andere ('The Other'). The main character was an irritable and overworked public prosecutor who, after falling into an exhausted sleep, during the night assumes his somnambulist 'second ego' as a thief, eventually burgling his own house in a state of somnambulism (Lindau, 1893; see also Cowan, 2004;Ellenberger, 2005: 242-4). Moll took Lindau's play as an illustration of Dessoir's concept of the 'double-ego'. In the Zeitschrift für Hypnotismus he commented on the play and praised Lindau for his excellent literary representation of a case of split consciousness, of a separation between 'upper consciousness' and 'subconsciousness'. Even the details in the portrayal of the character, such as transitional states between his two egos, were, according to Moll, in line with scientific experience. Through hypnosis, he explained, an individual's personality could be changed (Moll, 1892/93). 4 A film version of Der Andere, directed by Max Mack, came out in 1913 (Andriopoulos, 2008: 95-7;Cowan, 2004). It was one of numerous films at that time, including Robert Wiene's The Cabinet of Dr. Caligari (1919/20) and Fritz Lang's Dr. Mabuse, the Gambler (1922), which popularized the idea of crimes instigated by hypnotic suggestion (Andriopoulos, 2008: 91-127;Andriopoulos, 2009;Gunning, 2009). Commenting on this type of film, Moll (1924: 563-4) perceptively highlighted the 'suggestive power' of the medium 'film' as such and advised that the official boards of censors should examine such productions very critically.
Moll repeatedly took the occasion of relevant legal cases to comment on claims of hypnotic crime. For example, in January 1900 a woman and her lover were jointly on trial in Liegnitz (Silesia) for attempted murder of her husband. During the proceedings it was mentioned that she had made hypnotic experiments on her lover, the implication being that the attempted murder might have resulted from hypnotic suggestion in his case. Moll (1900) pointed out that it was in principle possible to instigate a crime in this way, but that because of the great danger of detection for the hypnotizer such cases were unlikely to occur, and that, in a case such as this, amorous passion or sexual dependence were more appropriate explanations. Soon Moll became an expert witness in court cases involving claims about hypnotic influence (Moll, 1904b;see also Anon., 1922;P.S., 1924). The most prominent case was that of the writer and hypnotist Leo Erichsen, which took place at the grand court of lay assessors in Hirschberg in 1927. Erichsen had been charged with having hypnotized and sexually abused a chambermaid in a hotel for two days. The accusation was that, in the pretence of treating her medically, he had carried out sexual manipulations on her genitals and raped her. The court of first instance followed  expert opinion that Erichsen had hypnotized the girl. It found Erichsen guilty of rape due to positive semen samples from the victim, and sentenced him under section 177 of the Penal Code to one and a half years of penal servitude for rape of a 'weakwilled' (willenlose) and 'unconscious' person. The court of appeal, however, reduced the sentence to six months imprisonment for bodily harm and insult, plus payment of 1000 Marks in compensation to the chambermaid. The allegation of rape could no longer be upheld, as the positive result of the test for semen (i.e. the microscopic detection of spermatozoa) was successfully challenged. Moreover, while the appeal court confirmed the state of lack of will in the victim, it was not convinced that Erichsen had really hypnotized her to produce this state, and left this question open. The court was apparently influenced in its decision by the opinion of a rival expert, the Berlin Professor of Neurology and Psychiatry Richard Henneberg (1868Henneberg ( -1962, who assumed merely a 'superficial hysterical daze' in the chambermaid when Erichsen carried out his sexual manipulations on her (Henneberg, 1928).
The Erichsen trial had a particular political significance at this time, as the official Draft for a new Penal Code (1925) had included the application of hypnosis -like that of narcotic drugs -as a form of using 'violence' (Gewalt) in making a person defenceless or unconscious (Ivers, 1927: 47-8;Moll, 1928/29: 110;Moll, 1930;Seelig, 1927). The outcome of the trial showed Moll the desirability of a much wider meaning of 'violence', including also other means of psychological influence, in the Penal Code. Without it, sexual abuse of a 'weak-willed' (willenlose) person, if it did not involve rape, could only be punished as a physical insult or physical injury (Moll, 1928/29: 114-15). Forensically, the Erichsen case raised again a question that had already been discussed in the hypnosis literature of the late nineteenth century: to what extent rape was possible under hypnosis (Lilienthal, 1887: 351-63). While Moll (1928: 22, 34-5) firmly asserted this possibility, on the basis of the literature and relevant cases known to him, Henneberg (1928: 192) doubted it, except for cases in which the victim suffered from feeble-mindedness. The danger of sexual abuse of hypnotized individuals had, however, been highlighted from the early days of the hypnosis debates: as early as 1887 Obersteiner had recommended that for this reason a third person should be present whenever an individual -female or male -was being hypnotized (Obersteiner, 1887: 77).

From hypnotism to psychotherapy
In the early 1900s, Moll took stock of the achievements of medical hypnosis in several articles and pamphlets addressed to medical professionals as well as general readers. In part, this reflection on the development of the field over the previous 15-20 years was motivated by an official enquiry about the therapeutic value of hypnosis and the use of this method by lay healers, which the Prussian Minister of Education had sent to doctors' chambers and regional governments in April 1902 (Schröder, 1995: 82-3). Being opposed to treatments by healers who were not medically qualified (the so-called Kurpfuscher) (Moll, 1915), Moll tried to show that hypnosis was an effective therapeutic method if it was competently applied by doctors (Moll, 1902b(Moll, , 1902c(Moll, , 1905a(Moll, , 1905b(Moll, , 1906(Moll, , 1907b. On the other hand, the reports collected in the Ministry enquiry did not reveal cases of harm to health through hypnosis by lay healers. 5 Moreover, a report of the Reichskanzler's office in July 1897 had concluded that 'suggestion-or psychotherapy' based on hypnosis was a legitimate and effective method of treatment for several functional, non-organic nervous diseases. 6 The Reichskanzler had therefore not seen any need to regulate hypnosis and suggestion therapy by law, and had merely proposed to collect the files of legal proceedings in which hypnosis played a role. 7 The proposal had been implemented by the Ministry of the Interior in the same year (Teichler, 2002: 192).
Another, more general background for Moll's renewed discussion of the topic was that the medical debates on hypnotic therapy had begun to die down and that other forms of psychological treatment had gained prominence (Janet, 1925, 1: 200-7;Schröder, 1995: 62-89). In the years around 1900, as Shamdasani (2005: 7-10, 13-16) has suggested, psychotherapy gained from the decline of interest in hypnosis by disassociating itself from the original method of hypnotic suggestion and defining its own, narrower therapeutic scope in the treatment of psychoneuroses. Sigmund Freud's use of the term 'psychoanalysis' for his own approach since 1896 allowed him, in turn, to distinguish his practice from the broader psychotherapeutic movement.
Moll argued that hypnosis had proved useful in two ways: as a therapeutic method itself, particularly in the form of hypnotic suggestion, and by drawing attention to the study of psychotherapy in general. An important step in the latter direction was the realization that therapeutic suggestions often also worked in the waking state (Moll, 1902b: 109;Moll, 1904c). Helpful psychotherapeutic methods were, in Moll's view, education and persuasion therapy (Belehrungstherapie), training of will-power (Willenstherapie), and occupational therapy (Beschäftigungstherapie) (Moll, 1905a(Moll, : 1217Moll, 1906: 301-2;Moll, 1907b: 514;Moll, 1924: 416-96). Moll took an eclectic attitude to such non-hypnotic methods, employing them in cases where he could not induce the hypnotic state (Moll, 1924: 421). He used training of will-power, for example, for the treatment of homosexuality and sexual perversions, methodically supporting 'normal' and suppressing 'abnormal' sexual ideas and associations -a method which he also called 'association therapy' (Assoziationstherapie) (Moll, 1911;Moll, 1924: 439-41;Moll, 1936: 57-9). In addition, Moll (1905aMoll ( : 1247 highlighted that the study of hypnosis had been important for forensic science, in particular through the realization that witness statements could be falsified by retroactive suggestions. In 1902 Moll briefly mentioned, without naming Freud, that hypnosis could enhance memory, allowing the identification of what had triggered certain obsessive ideas in a patient and subsequently to remove the symptoms through a specific procedure (Moll, 1902b: 110). Three years later, he referred explicitly to the cathartic method of Breuer and Freud (Moll, 1905a(Moll, : 1250. However, the personal and intellectual relations between Freud and Moll were characterized by mutual animosity and rivalry (Sauerteig, 2012;Sigusch, 2012). After World War I, Moll repeatedly expressed his critical position vis-à-vis psychoanalysis. In another review of the influence of the study of hypnosis, he criticized Freud's extensive use of 'the sexual' as an explanation for numerous nervous diseases (Moll, 1920: 282), and in a lecture in 1925 on 'modern psychotherapeutic methods' to the Berlin Medical Society he hinted also at 'moral dangers' of such 'digging into the sexual' (Wühlen im Sexuellen). While he did not reject psychoanalysis, he was sceptical about its therapeutic efficacy and concerned about the long duration of treatments, 'up to three years ' (Anon., 1925a;Anon., 1925b).
Moll's critical interest in the rise of psychoanalysis was likewise reflected in a new subsection on this topic in the fifth edition of his Der Hypnotismus (Moll, 1924: 469-88). Here he argued that sexual ideas and pathogenic events were often 'suggested into the patient' (hineinsuggeriert) by the analyst, and that cases of therapeutic success by psychoanalysis had more to do with its similarity to a confession. The patients actually knew very well what their problem was, and this knowledge was not hidden in their 'subconsciousness', but deliberately held back because of shame, fear or for other reasons (Moll, 1924: 480-2). Psychoanalysis, Moll claimed, might morally and psychologically harm some patients, particularly young girls, through 'hour-long discussions of sexual events and this artificial bringing-in of sexual interpretations' (p. 488). In general, however, Moll welcomed the increasing recognition of psychotherapeutic methods (pp. 488-91). From 1903 to 1935 he was, with only a short interruption (1924-7), chairman of the Berlin Society for Psychology and Characterology (Berliner Gesellschaft für Psychologie und Charakterologie), the renamed former Society for Experimental Psychology (Moll, 1936: 130-1; see also Kurzweg, 1976: 284-5); and from 1909 to 1924 he edited the Zeitschrift für Psychotherapie und medizinische Psychologie (Pranghofer, 2012: 297).
In his final work, his memoirs, published in 1936, Moll accused Freud of having contributed to the confusion of his 'the unconscious' (das Unbewußte) with the 'subconscious (das Unterbewußte) of Dessoir and Moll' (Moll, 1936: 70-1). 'The unconscious', Moll claimed, 'never becomes conscious, whereas the subconscious can already in the next moment be conscious' (Moll, 1936: 72, original italics). As mentioned above, in the context of his studies on the hypnotic rapport, Moll had assumed easy transitions of ideas from a person's 'subconsciousness' (Unterbewußtsein) to the 'upper consciousness' (Oberbewußtsein) and vice versa. Therefore, Moll's understanding of the 'subconscious' appears to have been closer to Freud's notion of das Vorbewußte than to the latter's general concept of the 'unconscious' (das Unbewußte). As Freud had explained in 1932, two kinds of 'unconscious' could be distinguished: one that could easily turn conscious under certain conditions and which had merely been latent; and another in which this change happened only with difficulty and after much effort, or maybe never. The former he called das Vorbewußte; for the latter he reserved the term das Unbewußte (Freud, 1972(Freud, [1932): 509).
Continuing his earlier criticisms, Moll (1936: 74) further claimed that the 'sexual Freudian analysis' had 'essentially foundered'. On the other hand, he admitted that his own 'association therapy' of sexual perversions had not found much resonance because of its limited scope and its demands on the patient's conscious will-power. Polemically, he contrasted his method with 'all the drivel about the unconscious and the lifting-up into the upper consciousness which is known to play such a big role in Freud's psychoanalysis' (Moll, 1936: 57-8

Conclusion
In retrospect, Moll's work has been overshadowed by Freud and psychoanalysis. In his time, Moll's expertise in hypnotism and suggestion therapy had been prominent. As this paper has shown, he successfully defended a psychological approach to nervous diseases; widely discussed the method of hypnotic suggestion for non-medical as well as medical readers; was involved alongside Dessoir in developing a theoretical understanding of hypnosis; and served as a critical expert in court cases of 'hypnotic crime'. He had some important allies, such as Forel and Krafft-Ebing, but was also confronted with significant opponents and competitors: Ewald, Mendel, Wundt, Henneberg and Freud. Throughout, Moll remained a tenacious adherent of the Nancy School. His prominence as a medical hypnotist was linked to the general rise and decline of public and medical interest in the method. Unlike Freud, Moll did not carve out a specific new approach when the movement towards 'modern', non-hypnotic psychotherapy developed. His 'association therapy' was little more than a special application of the wider psychotherapeutic training of willpower. Regarding his theory of hypnosis, Moll was clearly indebted to Dessoir's concept of the 'double-ego'. Moreover, Freud's psychoanalytic theory had greater interdisciplinary appeal and better connectivity for a variety of intellectuals than Moll's work (Sauerteig, 2012: 181). Moll's criticism of an over-sexualization of young patients in Freudian psychoanalytic therapy was not particularly original, being shared for example by the Breslau Professor of Psychology, William Stern (1871-1938) (Sauerteig, 2012: 178-9). Moll remained an authority in the field of hypnotism, but during the rise of psychotherapy he acted more like a knowledgeable, critical commentator and eclectic practitioner than an active researcher or innovator. Remaining throughout his professional life in private practice and not holding a university position, Moll may also have lacked opportunities for creating a psychotherapeutic school of his own, despite his roles as chairman of a society and a journal editor. Beyond this, however, Moll's work provides us with good insights into central issues of the hypnosis debate of the late nineteenth century: the therapeutic powers as well as dangers of hypnotic suggestion, and the understanding of hypnotic phenomena through the assumption of a subconscious sphere. In this sense, his publications in the field of hypnotism continue to be worthwhile reading.