Hallucination or materialization? The animism versus spiritism debate in late-19 th -century Germany

Introduction

In the recent historiography of modern occultism, psychical research and parapsychology in Germany, a number of historians have pointed to two late-19th-century debates, which proved significant in the disciplinary evolution of the so-called border sciences (Bauer, 1991; Pytlik, 2005; Sawicki, 2002; Treitel, 2004; Wolffram, 2009). These conflicts, known as the Zöllner debate and the animism versus spiritism or Hartmann versus Aksakow debate, highlight the bitter multi-frontal battles that took place during the closing decades of this century among German spiritists, psychical researchers and psychologists over the meaning and implications of the phenomena of the seance room. ¹ At stake in both of these debates was not only the question of whether spirits existed, but the parameters and proper object of the nascent field of psychology. Indeed, the combatants in these disputes were profoundly divided over whether this new field should concentrate solely on normal waking consciousness, the phenomena of which could be examined and measured using methods derived from physiology, or whether it should be allowed to include the study of abnormal and unconscious states such as somnambulism and mediumship. Although historians of the border sciences clearly agree that both of these debates were significant in articulating the issues surrounding the delimitation of psychology’s disciplinary boundaries during the late 19th century, they have tended to concentrate their analyses on the Zöllner debate. In comparison, the dispute between Hartmann and Aksakow, which coincided with the emergence of Germany’s first psychical research groups, the Munich-based Psychologische Gesellschaft [Psychological Society] (founded 1886) and the Berliner Gesellschaft für Experimental-Psychologie [Berlin Society for Experimental Psychology] (founded 1888), has been neglected. 

The reasons for this historiographical emphasis on the Zöllner debate are easy to assess. The events leading up to what became a very public argument involved a charismatic medium with a criminal history as well as several very well-known and highly respected scientists who chose to seriously investigate this medium’s phenomena. The debate itself not only involved critiques by some of Germany’s leading scientific figures in both journals and newspapers, but a sustained attack on the study of mediumship by one of the founders of the new experimental psychology. ² For those unfamiliar with this dispute the details are as follows: during the winter of 1877–8 the Leipzig-based astrophysicist Johann Karl Friedrich Zöllner (1834–82) conducted a series of experiments with the American medium Henry Slade (1835–1905) to which he invited a number of friends and colleagues from the University of Leipzig, including Gustav Fechner (1801–87), Carl Ludwig (1816–95), Wilhelm Scheibner (1826–1908), Carl Thiersch (1822–95), Wilhelm Weber (1804–91) and Wilhelm Wundt (1832–1920) (Treitel, 2004). Slade, who had arrived in Germany after narrowly escaping a prison sentence in Britain for fraud, produced an array of impressive phenomena during these experiments (Kohls and Benedikter, 2010). In Slade’s presence participants experienced mysterious writing on closed slate tablets, the appearance of knots in loops of leather, the imprint of ‘spirit’ hands in both flour and wax and the medium’s apparent capacity to access information through clairvoyance (Staubermann, 2001). Zöllner’s experiments convinced him that the phenomena he observed were genuine and were not a result of either careless observation by the sitters or physical manipulation by the medium (Zöllner, 1879). Indeed, he postulated, using a concept derived from non-Euclidean mathematics, that the strange phenomena he had witnessed in sittings with Slade were carried out by beings occupying a fourth dimension; an idea that he sought to use as the basis of a new science called Transzendentalphysik [Transcendental Physics] (Luttenberger, 1977: 195–214; Stromberg, 1989: 372–80).

Unsurprisingly, when Zöllner published these findings in 1878 and 1879 the response was dramatic (Zöllner, 1879). His theories were met with derision by prominent members of the scientific community, such as Emil du Bois-Reymond (1818–96), Ernst Haeckel (1834–1919), Hermann Helmholtz (1821–94) and Rudolf Virchow (1821–1902), who regarded Zöllner’s efforts both as a misapplication of scientific energy and as a possible signifier of his mental instability (Cahan, 1994; Treitel, 2004). The German spiritist community, however, lauded Zöllner’s publications, regarding his seance protocols as empirical proof for their belief in the survival and continued agency of the spirit after death; proof that was vouchsafed, they contended, by Zöllner’s immense scientific expertise and authority (Ulrici, 1879). In response to such spiritist polemics the psychologist Wilhelm Wundt, who had briefly attended one of Slade’s sittings, wrote a carefully considered analysis of ‘spiritism as a so-called scientific problem’ (Wundt, 1885). He argued that scientific expertise could not be transferred from one field to another and that the predictable function of natural law and causation made it more likely that witnesses to the phenomena of mediumship were mistaken than that natural law had been suspended or contravened (ibid.). Zöllner who felt that his personal and scientific reputation had been damaged by Wundt, threatened the psychologist with legal action (Kohls and Benedikter, 2010; Zöllner, 1879).

Historians have examined this debate from several perspectives using it as a means of understanding late-19th-century empiricism, theories of space perception and scientific authority as well as academic psychology’s confrontation with emergent fields such as spiritism and psychical research. In this latter type of analysis, Wundt, one of the leading figures in early experimental psychology who founded the first psychological laboratory in Leipzig in 1879, plays a pivotal role. ³ His rejection of spiritism and psychical research as legitimate branches of scientific endeavour and his denial of claims that psychology had a duty to investigate the strange phenomena of mediumship, have been seen by historians as attempts to protect the scientific credentials and epistemic scope of the nascent field of psychology (Wolf-Braun, 1998: 410; Marshall and Wendt, 1980: 165). As Corinna Treitel has shown, Wundt’s need to defend psychology in this context was intimately connected with the precarious position of the field within the German academic system during the late 19th century (Treitel, 2004: 21). But as a number of other scholars have demonstrated, Wundt’s reaction to the Zöllner debate was not simply defensive; the dispute helped him clarify the boundaries, competencies and objects of experimental psychology. As Niko Kohls and Roland Benedikter have argued, Wundt’s run in with the spiritists helped mould his conceptualization of scientific psychology, leading him to remove studies of altered states of consciousness from his research agenda; a move that involved limiting himself to the analysis of ordinary states of consciousness (Kohls and Benedikter, 2010: 47–50; Wundt, 1885). Such analyses make clear the potential that historians have seen in the Zöllner debate to provide crucial insights into the relationship between psychology, spiritism and psychical research during Germany’s Imperial period.

Although these same historians have frequently indicated the importance of the animism versus spiritism or Hartmann versus Aksakow debate, arguing that its introduction of several new hypotheses and specialist nomenclature proved significant for the disciplinary evolution of the border sciences in Germany, there has been little detailed analysis of it. ⁴ What is clear, however, is that in 1885, the popular philosopher and author of Philosophie des Unbewussten [Philosophy of the Unconscious] (1869), Eduard von Hartmann (1842–1906), published a book titled Der Spiritismus [Spiritism] in which he attempted to provide a comprehensive psychological explanation for the phenomena of the seance room (Hartmann, 1898). Hartmann’s hypotheses, which included shared hallucination to explain the phenomena of materialization, proved provocative for those who maintained that the physical excrescences of mediums were real objective phenomena (Pytlik, 2005). While several of those who actively experimented with mediums were critical of Hartmann’s theories it was Alexander Aksakow (1832–1903), editor of the leading spiritist periodical Psychische Studien [Psychical Studies], that provided the most thoroughgoing critique of his work (Bauer, 1991: 123–7). Aksakow’s two-volume book on this topic, which first appeared in 1890, demonstrated a strong conviction that he and others who subscribed to a spiritist interpretation of materialization were involved in a high-stakes epistemic battle against materialist experimental psychology; a psychology that in Aksakow’s opinion was represented not only by Wundt, but also by Hartmann (Aksakow, 1919: xvii–xxi). In reality, of course, the positions of Hartmann and Wundt differed in significant ways. Hartmann, who believed psychology, if it wished to become an independent science, must be based on an understanding of the unconscious and its phenomena, was willing not only to accept that some mediumistic phenomena were real, but to imagine a form of psychology which would, indeed had the responsibility to, include them in its research agenda (Hartmann, 1898; Hartmann, 1901: 30–1). This was a position that Hartmann had espoused as early as 1878 in the context of the Zöllner debate. While Wundt had rejected the need for any further investigation of the phenomena of mediumship during the dispute over Zöllner’s experiments, rejecting the possibility of a psychology based on such ill-defined and morally ambiguous phenomena, Hartmann had argued for the importance of psychological research in this field (Kohls and Benedikter, 2010: 48–50). ⁵ In a November 1878 letter to a Dr Gustav Bloede in New York, for instance, he granted the possible reality of the mediumistic phenomena witnessed by Zöllner, but attempted to explain them as products of the human unconscious rather than of spirits or beings occupying a fourth dimension (‘Kurze Notizen’, 1879: 332; Bloede, 1879: 361–6).

In assessing the relationship between psychology and the so-called border sciences during the late 19th century in Germany, the Zöllner debate has been a rewarding case-study for historians. It has demonstrated the indeterminate status of psychology during this period and the struggle between various interest groups, including physicists, experimental psychologists and spiritists, over its future (Treitel, 2004: 21–2). Indeed, the Zöllner debate makes evident that the proponents of the new experimental psychology within Germany’s universities, who sought to free psychology from philosophy and metaphysics by focusing on quantifiable conscious phenomena, had by no means established a monopoly over the mind by the closing decades of the 19th century, finding themselves in uncomfortable competition with groups outside the academy, including spiritists, psychical researchers and philosophers, who offered alternative models of the psyche and of psychology. In considering the relatively neglected animism versus spiritism or Hartmann versus Aksakow debate, which those within the universities during the 1880s and 1890s chose largely to ignore, this article will focus not just on the complex, multi-faceted conflict between academic psychologists and their competitors over the parameters and proper object of psychology, but also on the epistemological and methodological battles between these competitors over this field and in particular over the nature of the unconscious. ⁶ In so doing, this article intends to cast light on some of the boundary disputes that occurred over psychology in late-19th-century Germany and to argue that in this context, where the new discipline’s borders remained contested, men like Hartmann and Aksakow were just as much representatives of this ill-defined field as were Wundt and his colleagues.

Der Spiritismus

In his 1878 letter to Gustav Bloede, Eduard von Hartmann suggested that the phenomena exhibited by Slade and other spiritist mediums was best explained through recourse to the human unconscious, rather than the spirit world. He wrote:

What Hartmann argued with these four points was that all mediumistic phenomena could be understood as manifestations of the unconscious will of either the medium or the seance participants. ⁷ This idea was central not only to his correspondence with Bloede, but also to the more comprehensive analysis of spiritism, titled Der Spiritismus, which he published in 1885 (Hartmann, 1898). It was in this work that Hartmann made explicit the exact mechanisms through which he believed the medium’s unconscious will was given expression; these being primarily, magnetic rapport, thought-transference and hallucination.

The purpose of Hartmann’s book, which was the culmination of a decade-long interest in spiritism, appears to have been twofold. ⁸ First, he was committed to providing a natural explanation for the phenomena of spiritism. Like Wundt, Hartmann accepted that much mediumistic phenomena resulted from either conscious or unconscious manipulation, but unlike Wundt who used this fact to avoid further engagement in the field, Hartmann believed that fraud was not sufficient to explain all cases (Hartmann, 1898: 5–6). He maintained that those phenomena that could not be explained through reference to deception were indicative of as yet unexplored powers of the human organism; powers which desperately required a naturalistic explanation (ibid.: 23). Hartmann stressed that while the phenomena of the seance room may appear inexplicable, contemporary knowledge of natural laws and powers remained full of gaps, consequently it was by no means clear what was and was not possible in nature (ibid.: ii). He maintained that if one held fast to the belief that even apparently extraordinary phenomena were natural, three kinds of explanation were excluded: (1) that of the Catholic Church which was reliant upon devilish influence and demons; (2) that of modern theosophy and occultism that was reliant upon elemental spirits; and (3) that of spiritism that looked to the spirits of the dead (ibid.: ii–iii). What was left, according to Hartmann, was a psychological explanation, which looked to the unconscious for its explanatory power.

Hartmann’s second aim in Der Spiritismus was to encourage scientists to carry out research in this field and to convince governments to support such experimentation. He reminded both parties that there was widespread interest in the phenomena of mediumship and warned that spiritism threatened to become a public calamity (1898: 15). Hartmann argued that while an epidemic belief in spirits was dangerous because it promoted gullibility and fanaticism and provided multiple opportunities for swindlers, the a priori rejection of such phenomena advocated by Enlightenment dogmatists also represented a form of superficiality and lack of criticalness that did nothing to address this problem (ibid.). To the scientific community, therefore, he stressed that the public had the right to know whether these things were real or not and because they themselves were not capable of finding this out the task fell to scientific researchers (ibid.: 14–15). To governments he made clear that it was their duty to prevent unnecessary confusion and excitement in the minds of their citizens. Furthermore, he reminded the authorities that they possessed the means of easily settling the issue through scientific commissions (ibid.: 15). Such commissions were imperative for the collective good, according to Hartmann, who, while conscious that experimentation might be physically and mentally detrimental to mediums, maintained that the theoretical benefit of such research outweighed the possible harm to individuals (ibid.: 21). While Hartmann understood the reticence of researchers, who had up until now simply accepted science’s a priori rejection of spiritism, to dirty their hands in this peculiar field, he argued that historical and contemporary reports about the phenomena of mediumship made it clear that human beings appeared to possess unexplored powers, which needed careful research (ibid.: 14, 23).

In part, Hartmann’s stress on the necessity of other scientists conducting experimentation in this field was a result of the fact that he could not do so himself. As Adolf Kurzweg has written we cannot be sure what prevented Hartmann from taking part in spiritist sittings, but it was most probably his knee affliction, which tended to keep him house-bound (Kurzweg, 1976: 85). ⁹ Hartmann’s admission that he had never taken part in a mediumistic experiment and his declaration that he was therefore not qualified to pass judgement on the reality of spiritist phenomena, did not, however, prevent him from arguing that his training as a philosopher and his knowledge of the literature in the field licensed him to suggest appropriate experimental conditions and methodological rules as well as to draw some conclusions about the true source of these strange phenomena (Hartmann, 1898: 23). In a field in which fraud was a strong possibility because of the economic dependence of mediums on spiritist circles and their peculiar sensitivity to hostility on the part of experimenters, it was necessary, he maintained, to establish rigorous experimental controls that prevented deception while acknowledging that mediumistic productions differed from ordinary phenomena. Expanding on his argument that knowledge of natural law was incomplete, Hartmann stressed that researchers could not simply transfer the experimental conditions applied in other sciences – for example, the use of bright lights – to the field of mediumship (Kurzweg, 1976: 87). Instead, he suggested a series of devices and measures, partially independent of the control people, intended to prevent deception and fraud. Because mediumistic training and temperament made darkened sittings difficult to avoid, for example, Hartmann recommended that the sleeves, the boots and the hat of the medium should be marked with fluorescent colour or that the room should be illuminated by very dim phosphorescent light; the intention being to make each part of the medium’s body visible, while not disrupting his or her power with harsh electric illumination (Hartmann, 1898: 10). In order to prove the objectivity of physical phenomena such as materialized limbs, Hartmann demanded that there be physical evidence of their appearance, such as impressions in wax and plaster. Besides these measures to prevent fraud and sensory deception, Hartmann also established a set of methodological guidelines which the experimenter should observe when considering these phenomena. First, he stated, one should not look for multiple explanations where a single explanation was sufficient (ibid.: 117–18). Second, he reminded experimenters that one should as long as possible abide by those explanations that have been definitively proven and avoid those that are speculative or unproven (ibid.: 118). Third, he argued, one should as long as possible seek to find the source of phenomena in the natural world and resort to supernatural explanations only when natural explanations are exhausted (ibid.). Finally, Hartmann recommended that experimenters move from the simplest to the most complex phenomena in their experimental series, that is, from simple phenomena such as empathetic readings through to complex phenomena such as the transference of hallucinations to others based on a telepathic reading of their memories and unconscious (Hartmann, 1885: 505). Applying these rules, which excluded supernatural causation where a natural explanation could be found, Hartmann drew a series of conclusions that formed the basis for his thoroughgoing psychological theory of both the intellectual and physical phenomena of mediumship (Kurzweg, 1976: 88).

Hartmann’s study of the phenomena of the seance room suggested that all mediumistic activity, including table turning, automatic writing, trance speech, materialization and telekinesis, had their genesis in what the English physiologist W. B. Carpenter (1813–85) had called unconscious cerebration, but what Hartmann chose to call masked somnambulism (Hartmann, 1898: 30–1). In this state, which was often difficult to distinguish from waking consciousness, mediums wrongly ascribed the intelligent messages and hallucinatory images generated by their unconscious to strange invisible personified intelligences or spirits. Convinced that they were conduits to the other world, mediums therefore unconsciously used their nervous energy and their strong magnetic power, to transfer this belief and their hallucinations to those around them (Hartmann, 1887: 9). According to Hartmann, this process was aided not only by drawing on the nervous power of the sitters, who were lulled into a half-hypnotic state, but also through a telepathic rapport, which enabled access to sitters’ minds and memories thereby furnishing material for putative ‘spirit’ messages (ibid.: 10). Hartmann also acknowledged that in some instances such information might derive from a clairvoyant connection between the medium and what he called the Absolute (Hartmann, 1898: 78–81); an idea that he had begun to develop as early as 1869 in his Philosophie des Unbewussten. In this view, then, mediumistic communications derived almost entirely from the unconscious of either the medium or the sitters and materializations were simply shared hallucinations with no objective reality that were transmitted by the medium to the seance participants. Even in cases where there supposedly existed evidence of material or plastic effects brought about by mediumistic activity, such as the impression of ‘spirit’ limbs in putty or the movement of objects around a room, Hartmann, pre-empting by several decades the work of vitalist philosophers and parapsychologists such as Henri Bergson (1859–1941) and Hans Driesch (1867–1941), claimed that these phenomena derived from the somnambulistic fantasy of the medium and the material outgrowth of the medium’s organism, rather than spirit intervention (Hartmann, 1898: 36–40). ¹⁰

While Hartmann’s claim in Der Spiritismus that automatic writing, trance speech and thought transference were products of the unconscious was not particularly new or controversial, the application of this same theory to the physical phenomena of mediumship was. ¹¹ According to Hartmann, materializations, when they were not the product of fraud, possessed no objective reality existing only as hallucinations transferred from the somnambulistic consciousness of the medium to the sitters. His proof for this contention was that materializations did not appear for those people attending a seance for the first time (Hartmann, 1887: 10; Hartmann, 1898: 90). According to Hartmann it often took numerous sittings with the same medium before participants experienced any phenomena because of the tight magnetic rapport required between the medium and the sitters successfully to produce any ‘materializations’ (Hartmann, 1887: 10; Hartmann, 1898: 91). Both a passive mental state and a positive interest in the appearance of phenomena also appeared to be necessary in order for the medium’s hallucinations to be transferred to the seance participants (Hartmann, 1887: 9–10). Aware that many people steadfastly argued in the face of sceptics’ criticisms that the materializations they had witnessed had an objective reality, having been perceived via healthy and uncompromised senses, Hartmann stressed that this conviction was also transferred by the medium (ibid.: 11). The claim that both individuals and groups could be persuaded to see things that were not there or to share the same visions had, Hartmann maintained, a number of precedents. A compelling contemporary example was evident in the performances of stage magnetizers and hypnotists who persuaded their subjects that the sticks they held were snakes, that the onions they were eating were apples and that people could fly through the air (Hartmann, 1898: 94). The history of ecstatic religious visions and that of second sight were also educative according to Hartmann, who noted that mass visions and the supernormal transfer of information gleaned through second sight were well documented (Hartmann, 1887: 8–9). What lacked documentation, however, was the objective reality of materializations. While some people claimed that spirit or materialization photographs provided compelling evidence of this reality, Hartmann argued that even when the medium and their materialization appeared in the same image, thereby proving that the apparition was not simply the medium in disguise, the majority of these pictures were still quite clearly fraudulent (Hartmann, 1898: 97–8). For those researchers invested in a spiritist interpretation of the phenomena of the seance room, these arguments were to prove extremely provocative.

Hallucination or materialization?

The appearance of Der Spiritismus in 1885 elicited much excitement among those with an interest in psychical research and spiritism not least because it appeared to demonstrate that scientists were finally taking the phenomena of mediumship seriously. Aksakow, for example, was convinced that the fact that a renowned public intellectual such as Hartmann had chosen to engage in serious consideration of mediumistic phenomena indicated that his years of tireless effort in the promotion of spiritism had finally begun to pay dividends (Aksakow, 1919: lxxxv). Moritz Wirth writing in Psychische Studien claimed that there was hardly an expression of praise too great for Hartmann’s work, which had saved the honour of German thinkers and German science by espousing exact research and no ghosts (Wirth, 1885: 403–6). Indeed, even those most critical of Hartmann’s theories had to admit that he had done much to promote the field among scientists. The philosopher and spiritist Carl du Prel (1839–99), for example, disagreed with Hartmann on many points, but wrote nonetheless, ‘Whoever is interested in the area of mysticism will in any case be thankful that despite the prevailing prejudices you have written about it’ (Du Prel, 1885a; 1885b: 104). Similarly, in an article on spiritism and science in Germany that appeared in Sphinx in 1886, Carl Sellin stated that given Wundt’s rejection of spiritism during the Zöllner debate, one should not underestimate the service that Hartmann had done in highlighting the responsibility of official science to take a position on the phenomena of the seance room (Sellin, 1886a: 21). Notwithstanding this praise, Sellin and others critical of the psychological explanation of mediumistic phenomena that Hartmann’s book promoted felt justified in arguing not only that the philosopher was wrong, but that his work was both illogical and unscientific (ibid.: 13).

One of the critics’ central complaints was Hartmann’s ostensible rejection of the expertise and authority of those scientists, including William Crookes (1832–1919), Cromwell Fleetwood Varley (1828–83), Alfred Russell Wallace (1823–1913), and J. K. F. Zöllner, who had experimented with mediums during the preceding thirty years. Sellin, for instance, argued that while Hartmann’s experimental method appeared well founded and his methodological guidelines, which recommended both experimental and explanatory progression from simple to more complex, sounded very nice, men such as Crookes, Varley, Wallace and Zöllner had fulfilled these conditions decades ago during long experimental series (Sellin, 1886b: 294). While Sellin, in defence of Alexander Aksakow’s heavy reliance on the seance protocols of Crookes and Zöllner, acknowledged that there was a difficulty for researchers who desired their own experiences of materialization, he maintained that the material provided by these scientists could serve as a substitute for one’s own experiments due to its scientific rigor. Hartmann, however, had largely rejected this material, claiming that Crookes and Zöllner were not ‘classic witnesses’, and had intimated that these renowned experimenters had been subject to hallucination, despite what Aksakow and Sellin regarded as their adherence to strict scientific method (Sellin, 1886b: 290–2; Hartmann, 1898: 16–19). Like Wundt during the Zöllner debate, Hartmann appeared to believe that neither the expertise nor the authority that a scientist had accumulated in one field could be transferred unproblematically to another (Hübbe-Schleiden, 1887: 112–13). ¹² But while Hartmann’s apparent denigration of scientific authority in Der Spiritismus was disappointing for his spiritist critics, their real objections were directed at his theorization of the phenomena of the seance room.

Hartmann’s attempt at a naturalistic theory of the phenomena of mediumship, grounded in both the philosophy and psychology of the unconscious, was according to his critics based upon a number of flawed and a priori assumptions. The first was that mediumistic phenomena derived from a nervous force within the medium, which  manifested itself not only in extra-sensory powers, but also in the production of mechanical and plastic effects outside the human body (Hübbe-Schleiden, 1887: 107). The second was that the apparently objective experiences of people who witnessed mediumistic phenomena were a result of hallucinations (often collective), which derived from this same nervous force (ibid.: 107). The third assumption, which harked back to Hartmann’s 1878 letter to Bloede, was that there existed a hidden somnambulistic consciousness throughout a subject’s normal life, which could telepathically access the whole past and present life of another person (Myers, 1889/90: 665). The final assumption was that this somnambulistic consciousness sometimes exhibited clairvoyant power and could in this manner connect with the Absolute thereby gaining access to knowledge of all that is or has ever been (ibid.: 665–6).

The assumption that mediumistic phenomena both psychical and physical derived from a nervous force within the medium was not necessarily disputed by those critical of Hartmann’s book. For Aksakow, who maintained that the greatest error of spiritism was to ascribe all phenomena to a single cause, i.e. spirits, this idea was compatible with two of the three hypotheses which he argued could legitimately be used to comprehend mediumistic phenomena (Aksakow, 1919: xxix). It was possible, for instance, that phenomena such as automatic writing, communication through the turning or rapping of tables and trance speech, which occurred within the limits of the medium’s body and involved an apparently strange personality, derived from the unconscious. Aksakow called this theory ‘personism’ (Personismus). In contrast, ‘animism’ (Animismus) involved unconscious psychical phenomena that were exhibited beyond the limits of the medium’s body; for instance, thought-transference, telepathy, telekinesis and materialization. ¹³ Here the psychical element which could have both psychical and physical effects on the outer world was shown to be an actual centre of force. According to Aksakow, the final hypothesis which could be applied to these phenomena was that of ‘spiritism’ (Spiritismus), which involved phenomena resembling both ‘personism’ and ‘animism’, but which could only be ascribed to intelligent beings outside the medium and beyond the earthly realm, that is, to spirits. The use of ‘personism’ or ‘animism’ to explain a particular phenomenon was not at issue, indeed these hypotheses provided the most likely explanations in many cases; what was disputed, however, by Aksakow and other critics, including Carl Sellin and Wilhelm Hübbe-Schleiden (1846–1916), was the use of the first and the second theories to the exclusion of the third.

It was in this context then, in which Hartmann employed a comprehensive animistic theory of the phenomena of mediumship to mould the public’s understanding of spiritism, that spiritists went on the offensive. The man leading the attack was Aksakow who over a period of four years wrote a long series of articles, initially published in Psychische Studien but subsequently published in book form as Animismus und Spiritismus (1st edition 1890), in which he sought to discredit Hartmann’s hallucination hypothesis and to establish the reality of spiritism. Aksakow and his supporters were firm in their belief that the physical phenomena of mediumship were not hallucinations, but objective events, which could only be adequately explained through reference to the spirit hypothesis, that is, the theory that at least some of the phenomena were caused by the spirits of the dead. In Aksakow’s articles and book he set out to prove this theory by citing the meticulous seance protocols of renowned scientists, indicating photographs which captured mediums with their materializations, and analysing the content of putative spirit messages. In this way, Aksakow stated in the foreword to Animismus und Spiritismus [Animism and Spiritism], he was simply applying the critical method recommended by Hartmann to the discussion of mediumistic facts, rather than mounting a defence of spiritism (Aksakow, 1919: xxiii). The results of this application of Hartmann’s method, however, were predictably used by Aksakow as evidence against the hallucination hypothesis and for the truth of spiritism.

Hartmann’s assumption that apparently objective phenomena witnessed by people around the world and throughout history were merely hallucinations projected by the mind of a medium seemed patently false to many of those who had conducted research in this field. Sellin, for example, argued that it was impossible that the millions of people who had seen materializations, perceiving them just as they would any other objective phenomena, had all been subject to hallucination or illusion. If this were the case then every perception made by these people should be regarded as a hallucination (Sellin, 1886b: 298). Sellin maintained that Hartmann’s fundamental error lay in his unsupported assumption that everyone who participated in spiritist sittings, that is, educated observers as well as sensitive and suggestible people, were subject to the medium’s hallucinations (ibid.: 291). This error created a serious contradiction, Sellin maintained, between the philosopher’s aims and his hypothesis. Hartmann had, for instance, encouraged scientists to conduct research and to collect evidence in this field, but had simultaneously insisted that one’s impartiality stood in inverse relation to the number of sittings one attended (ibid.: 291–2). He had declared in Der Spiritismus, that:

I believe that in this field of phenomena, where certain hallucinations for the medium are nearly a condition for the appearance of certain phenomena, and those present more or less stand under the magnetic influence of the medium and under the contagion of their hallucinations, that complete impartiality of judgement through frequent participation in mediumistic sittings with psychological necessity becomes impaired, it is very difficult for those researchers who through frequent sittings fall under the power of the medium and their hallucinations. (Hartmann, 1898: 23–4)

Sellin argued that Hartmann’s hallucination theory privileged the philosopher, who could remain impartial in his study, while ensuring that compelling evidence for the reality of mediumistic phenomena could not be obtained through experimentation (Sellin, 1886b: 291). What Sellin perhaps ignored here was that Hartmann’s emphasis upon the suggestive atmosphere of the seance room and the fallibility of the senses was not intended to negate the role of experimentation in this field, but to highlight the need to make controls and evidence as independent from the experimenter as possible. ¹⁴

It was this need for objective evidence free from the problems associated with sensory perception that had led Hartmann to insist in Der Spiritismus that the reality of the physical phenomena of mediumship could be established only by the tangible forms of evidence left in their wake. This evidence could consist of images on photographic plates, phonographic recordings (if the phenomena were auditory), or impressions in wax or plaster of materialized forms. Such evidence, however, needed to be collected under conditions that conclusively excluded fraud. Hartmann required, for instance, that materialization photographs feature both the medium and her or his materialization in the same image to exclude the possibility that the medium was simply engaged in an elaborate form of mummery (Hartmann, 1885: 507–8). While Hartmann remained convinced that there were few if any photographs of mediumistic phenomena that were genuine, his critics maintained that there was compelling photographic evidence that at least some materialization phenomena had an objective reality. Indeed, the first volume of Aksakow’s book was dedicated to dispelling the hallucination theory through the analysis of such photographic material. In this forum, Aksakow alerted his readers to a multitude of examples in which respected scientists such as Crookes, who could not reasonably be accused of fraud or lack of scientific rigor, had managed to photographically capture their mediums with materialized forms (Sellin, 1886b: 299). To Aksakow and his supporters these photographs seemed to seriously undermine Hartmann’s contention that materializations appeared only in the minds of seance participants. Hartmann’s ‘unscientific’ hallucination theory was also weakened these critics argued by the philosopher’s inconsistent and illogical application of it (Hübbe-Schleiden, 1887: 109).

Although Hartmann had insisted that so-called materialization phenomena, which included whole or partial apparitions in both human and inchoate form, were a product of hallucination and had no objective reality, he had also maintained that other types of physical phenomena, such as telekinesis and materialized limbs, might exist, if only temporarily, in the physical world. Aksakow pointed to this apparent contradiction when he cited Hartmann as saying of the wax impressions made by ‘spirit’ limbs that these phenomena provided evidence that one was not dealing, in this case at least, with the implantation of hallucinations (Aksakow, 1919: 151). Aksakow wondered therefore how Hartmann explained these objective phenomena. Unlike others approaching this problem from the position of positive science, Aksakow said, Hartmann did not simply declare that a human limb was responsible for such impressions, instead he stayed true to his theory of nerve energy and argued for the operation of pushing and pulling lines of the medium’s nervous energy projected outside the body to affect movement and change in the physical world (ibid.). If, however, observers thought they saw a materialized hand causing these movements, Aksakow stated, this perception was entirely hallucinatory; this meant that in Hartmann’s conceptualization of such phenomena the effects were real but their outward appearances were not (ibid.: 151–2). What sort of logic or scientific reasoning, Aksakow asked, was Hartmann using here? According to the editor of the occult journal Sphinx, Wilhelm Hübbe-Schleiden (1846–1916), Hartmann’s hypotheses depended not only on a belief in the effect of unconscious psychological powers (that is, the medium’s nervous energy), but an acceptance of post-Kantian ideas about matter where material objects were regarded as constructions derived from our three-dimensional perception of the effects of energy (Hübbe-Schleiden, 1887: 109). While this dynamic understanding of matter might in theory help explain a range of mediumistic phenomena neither Aksakow nor Hübbe-Schleiden was convinced that there was convincing evidence for the direct material expression of thoughts and ideas that was implied in this theory (ibid.: 110).

In presenting what he was convinced was compelling photographic evidence of the objective reality of mediumistic phenomena and in attacking the theoretical edifice in which his opponent sought to cloak his illogical and a priori assumptions, Aksakow believed he had gone a long way towards disproving Hartmann’s hallucination hypothesis. In spite of this success Aksakow was aware that disproving the prevalence of hallucination in the seance room did not in fact prove the spiritist hypothesis. While he was adamant that he had established the reality of the physical phenomena of mediumship, he was conscious that their cause could still be interpreted as animistic, that is, somehow deriving from the medium’s mind and organism. Agreeing with Hartmann, who had tried to separate the question of materialization from that of the reality of spirits and had pointed to ‘spirit’ messages as a litmus test, Aksakow argued that the spiritist origin of mediumistic phenomena could only be proven through close analysis of putative spirit communications (Hartmann, 1885: 506). It was such an analysis that he undertook in the second volume of Animismus und Spiritismus.

While many critics agreed with Hartmann that some of the information that mediums produced in seances resulted from a telepathic transference of the thoughts and memories of those in attendance, they were unwilling to accept that the medium’s powers might extend to telepathic connection with anyone in the world or clairvoyant connection to the Absolute. For these critics it seemed far more probable that mediums derived this information from spirits. In Der Spiritismus, Hartmann had by and large explained ‘spirit’ messages through recourse to the somnambulistic consciousness of the medium and the sitters and telepathic transference between them. When the second volume of Aksakow’s book appeared to demonstrate that there existed cases in which the content of such messages could not have come from anyone in the seance room, however, Hartmann wrote another pamphlet titled Die Geisterhypothese des Spiritismus und seine Phantome [The Ghost Hypothesis of Spiritism and its Phantoms] (1891) in which the somnambulistic consciousness became all but omnipotent through clairvoyant access to the World Substance. His critics claimed that Aksakow had abided by Hartmann’s methodological and evidentiary rules to disprove the hallucination hypothesis and demonstrate the probability of spirit intervention and in response the philosopher had extended the medium’s powers until they were no longer restricted by time and space (Aksakow, 1919: xiv). In so doing, these critics intimated, Hartmann was no longer restricted by logic or science.

Du Prel’s critique

Due to poor eyesight and poor health, Aksakow found himself unable to provide a response to Hartmann’s Die Geisterhypothese (Aksakow, 1919: xii). On his behalf, however, the philosopher Carl du Prel, one of the founders of Germany’s first psychical research group, the Munich-based Psychologische Gesellschaft, took up the gauntlet. For du Prel this defence offered an opportunity to reprosecute the case for a transcendental interpretation of mediumship that he had lost within the Munich society during the late 1880s. Germany’s early psychical research groups, critical of the ascendancy of physiological psychology in Germany’s universities, had set out to establish an experimental psychology based on the hypnotic exploration of altered states such as somnambulism and spiritist mediumship that would free contemporary psychology from what they regarded as its false materialistic position (‘Programm der psychologischen Gesellschaft’, 1887: 33). The Psychologische Gesellschaft in Munich and the Gesellschaft für Experimental-Psychologie in Berlin envisaged research into these phenomena as a means of correcting the new physiological psychology and as a crucial step towards a more holistic approach to the mind (‘Programm der Gesellschaft für Experimental-Psychologie’, 1888: 299). There were tensions, however, within these societies, which paralleled those of the contemporaneous animism versus spiritism debate, over how the phenomena of the seance room were to be interpreted. In the case of the Munich society these led to a split in 1889 between those like du Prel who looked to a spiritist explanation and those like his colleague Albert von Schrenck-Notzing (1862–1929), who, in a fashion similar to that of Hartmann, rejected the spirit hypothesis and looked to the unexplored depths of the mind to explain paranormal phenomena. But while du Prel’s desire to defend both Aksakow and the spiritist hypothesis was important, his need to criticize Hartmann undoubtedly also played a role here. As Andreas Sommer has indicated, the deterioration of the relationship between du Prel and Hartmann, which had been fostered by many years of correspondence, had its roots in Hartmann’s critique of du Prel’s transcendental individualism, the central feature of his book titled Die Philosophie der Mystik [Philosophy of Mysticism] (1885), in an essay titled ‘Somnambulism’ (Hartmann, 1886; Kaiser, 2008; Sommer, 2009: 60). Du Prel thus used this opportunity to support Aksakow, to criticize Hartmann, and to defend his theory of the transcendental subject. 

Hartmann’s rejection of the spirit hypothesis and fetishization of the unconscious had set up, according to du Prel, an inflexible either/or theory that did not fit the facts of mediumship (Du Prel, 1891: 259). What Aksakow had made apparent in his response to Hartmann’s Der Spiritismus was that only some of these phenomena came from the medium’s unconscious and that the remainder were caused by spirits. Du Prel argued that the apparent dualism in this stance was not problematic if one considered that the abilities of spirits must be latent in our unconscious, showing themselves only in abnormal states as portents of post-mortem power (ibid.). As post-mortem survival of the personality was excluded from Hartmann’s philosophical system, in which the unconscious was collective rather than individual (Hartmann, 1869), he was forced, du Prel claimed, to seek the source of spiritist phenomena in the medium’s unconscious and was reliant on arcane and procrustean explanations involving unconscious connections to the world substance or Absolute to account for Aksakow’s examples of clairvoyance in space and time (Du Prel, 1891: 260). Indeed, Hartmann’s second book offered nothing substantive in response to Aksakow’s critique, relying on a priori hypotheses and ‘back doors’ to avoid awkward facts. Given Hartmann’s failure to reconsider those phenomena that Aksakow had demonstrated were not explicable via his theories, du Prel found it particularly galling that the philosopher could continue to claim that the spiritist explanation was unscientific (ibid.: 261, 266).

For du Prel, Hartmann’s inability to understand the role played by invisible intelligences or spirits in the production of mediumistic phenomena was a direct result of his ignorance of the extensive literature on somnambulism, which had grown steadily since the time of Mesmer (ibid.: 260). According to du Prel, Hartmann, the so-called philosopher of the unconscious, was familiar with only a small part of this subterranean realm; the part apparent in dreams, in madness and various other abnormal states. He wrote:

In a word: Hartmann knows only the physiological unconscious and behind this the unconscious as the world substance. That between these two lies yet a transcendental subject he is unaware and will remain so as long as he refuses to study somnambulism. Only in this way is it explicable that he still maintains the basic error of his system: the limitation of our individuality to our earthly form. In place of the continuance of this individuality for him steps its absorption by the world substance. (Du Prel, 1891: 260)

Failure to acknowledge the transcendental subject rendered Hartmann’s analysis of the unconscious superficial; for Hartmann, du Prel declared, the unconscious was purely physiological, a more or less homogenous mass without psychological subdivision (1891: 269). If Hartmann had truly studied somnambulism he would know that the unconscious was free of the organism and he could no longer refuse to take the step from physiological psychology to transcendental psychology, becoming for the first time a true ‘philosopher of the unconscious’ (ibid.: 270).

Defining the unconscious

Clearly for Du Prel and other spiritist critics, Hartmann was a representative of physiological psychology, whose approach to the phenomena of mediumship could be conflated with that of Wundt. But while he may have shared Wundt’s desire to understand the world without recourse to supernatural explanation, Hartmann was clearly opposed to the psychologist’s a priori rejection of a whole class of phenomena that he had not yet examined (Hartmann, 1898: 22). Hartmann’s approach to the phenomena of the seance room and to the field of psychology in general was quite distinct from that of Wundt and other psychologists working within Germany’s universities (Hall, 1912: 230–2). In forging a career outside of the academy, Hartmann enjoyed the freedom to combine philosophy, psychology and metaphysics in ways that were becoming increasingly unacceptable within the universities in the second half of the 19th century (ibid.: 183). In the academy, the new scientific psychology sought to isolate itself from philosophy and metaphysics, focusing exclusively on conscious phenomena and using methods derived from physiology and physics in order to secure its own niche, distinct from that of philosophy, within the university system. Many psychological researchers outside the universities, however, including popular philosophers like Hartmann and members of Germany’s psychical research community, were critical of the narrow parameters of academic psychology, insisting that consciousness could not be fully understood without recourse to the unconscious and its phenomena (ibid.: 231–2). In the years in which the debate between Aksakow and Hartmann took place, contemporary psychology was thus divided over whether this nascent field should focus solely on normal waking consciousness or whether it should be allowed to include the study of unconscious states such as somnambulism and mediumship. The uncertainty around these epistemological and methodological questions reflected the as yet inchoate status of this aspiring discipline and allowed its borders to be contested by a range of interest groups who all wished to gain a monopoly over the mind. While the Zöllner debate has demonstrated how the new scientific psychology responded to this unwelcome competition, the Hartmann–Aksakow dispute highlights the divisions between those who argued that the new scientific psychology was both materialistic and epistemologically deficient because of its refusal to engage with the unconscious. What divided the participants in the animism versus spiritism dispute were their differing understandings of this murky realm and what constituted an adequate explanation for the phenomena exhibited in unconscious states.

For Hartmann the unconscious, a trans-individual and collective phenomenon, was central not only to his understanding of spiritism, but also to his understanding of psychology. His enormously popular Philosophie des Unbewussten, first published in 1869 as an attempt to combine German idealism and the natural sciences, saw the unconscious represented as an atemporal, aspatial phenomenon responsible for the formation of both the organism and its consciousness and significant for its epistemological, physical, psychological and metaphysical implications (Shamdasani, 2003: 175–6). While Hartmann indicated the importance of the unconscious for psychology in this two-volume work, it was in his 1901 book Die Moderne Psychologie [Modern Psychology], which purported to be a history of psychology in the second half of the 19th century, but was in fact a polemic against physiological psychology (Geuter, 1983: 200), that he made explicit his conviction that psychology must be based on the unconscious (Hartmann, 1901: 30–1; Geuter, 1983: 200–1). The attempt to base psychology solely on the conscious mind was, Hartmann argued, impossible. If psychology wanted to become an independent science apart from physiology it must deal with immaterial unconscious mental life (Hartmann, 1901: 30). While those within the academy tended to be either critical or dismissive of Hartmann’s approach to psychology (Shamdasani, 2003: 177), as demonstrated by Wundt’s choice to exclude Die Moderne Psychologie from his 1907 list of all the psychological literature of the preceding 20 years (Hall, 1912: 232), the philosopher’s advocacy of the unconscious as the basis of a holistic scientific psychology had its supporters among psychological researchers outside the universities, including members of the psychical research community.

All of those within Germany’s psychical research societies, whether animists like Schrenck-Notzing or spiritists like Aksakow and Du Prel, would have agreed with Hartmann that the phenomena of the unconscious were crucial for the establishment of a holistic psychology and that the phenomena of spiritism could not simply be ignored by science. But while Schrenck-Notzing praised the version of the unconscious featured in Hartmann’s Der Spiritismus, because it made the spirit hypothesis superfluous (Schrenck-Notzing, 1920: 30), Aksakow and Du Prel rejected the philosopher’s definition. For these researchers the unconscious was individual, rather than collective, although it shared with Hartmann’s model an atemporal and aspatial character (Du Prel, 1885b: 105). While death, according to Hartmann’s theory, saw the individual’s unconscious absorbed back into the Absolute, the transcendental ego of Du Prel was simply unharnessed from the body and remained capable of communicating in disembodied form (Du Prel, 1885a.) Hartmann contended that there were indications of his collective and trans-individual unconscious in the ability of mediums and somnambulists to access information clairvoyantly from the World Substance as well as telepathically from seance participants, researchers like Aksakow and Du Prel, however, argued that these same feats pointed to the ego’s survival of death (Du Prel, 1885b). In using a definition of the unconscious that avoided a personalized survival, Hartmann was able to claim that the theories he proposed in Der Spiritismus were psychological and naturalistic. This was, however, disputed by Aksakow and Du Prel who regarded the use of the Absolute as unscientific and illogical; a procrustean device that enabled Hartmann to circumvent natural law and avoid the incontrovertible proof presented by spiritists of the soul’s survival of death. Unable to come to a consensus on this matter, both sides resorted, as we have seen, to attempting to undermine their opponent’s objectivity, method and scientific credentials.

Conclusion

In their battle over the unconscious and its parameters and in their different conceptions of what constituted psychology and the criteria for its scientific status, Hartmann, Aksakow and their supporters helped demonstrate not only the multiple understandings of the unconscious that circulated during the late 19th and early 20th centuries, but the vastness and disunity of contemporary psychology itself. As Sonu Shamdasani has shown, the term ‘psychology’ like the term ‘unconscious’ papered over and covered up the incommensurabilities, the cleavages and epistemological anarchy that existed in attempts to establish an independent science of the mind in this period (Shamdasani, 2003: 8). In order to mould a consensus from this chaos, Hartmann and Aksakow like Wundt and the spiritists resorted to various forms of boundary-work to legitimate their stance and to delegitimize that of their opponents; a strategy that tended to make the boundaries between these different psychologies more explicit. In the course of the Zöllner dispute, for example, the attempt to delegitimize the experiments of the spiritists helped Wundt more clearly define the borders of his psychology and its proper object. For those involved in the Hartmann–Aksakow debate the two parties’ advocacy and defence of different models of the unconscious led to a split within the psychical research community between animists, who sought naturalistic explanations for mediumistic phenomena, and spiritists, who continued to see their experiments as proof of the immortality of the soul.

For historians of psychology, spiritism and psychical research, the animism versus spiritism debate along with the Zöllner dispute remind us that the so-called pseudo-sciences should not be excluded from our discussions of psychology’s history and development, if we are to achieve a more comprehensive understanding of late-19th- and early- 20th-century psychological thought. The disputes between academic psychologists, popular philosophers, psychical researchers and spiritists over the strange phenomena exhibited in unconscious states and witnessed in seance rooms not only demonstrate the multiple versions of psychology that existed in this period, but help clarify the parameters, objects and methodologies of these different psychologies. Hartmann and Aksakow in their pursuit of a new scientific psychology based on the phenomena of the unconscious, albeit different versions of the unconscious, were thus just as much representatives of contemporary psychology as were Wundt and his colleagues. It is an appreciation of this fact that will help us better understand the complex and intertwined histories of psychology, spiritism and psychical research both in Germany and elsewhere.