1 Introduction

The German physician Franz Friedrich Anton Mesmer (1734-1815) discovered animal magnetism (Ocaña et al., 2015), a phenomenon that is considered the precursor of hypnosis (cf. Crabtree, 2019), a therapeutic method that played a significant role in 19^th-century medicine and has survived until the present day (Geagea et al., 2024).¹

Mesmer was interested in magnetism since his formative years at the University of Vienna, from 1760 to1766. Building upon the works of Johannes Kepler (1571-1630) on planetary motions, Isaac Newton (1643-1727) on gravitation, and Richard Mead (1673-1754) on «atmospheric tides,» Mesmer presented his doctrine on what he called gravitus animalis −i.e., animal gravitation− in his doctoral thesis in Medicine (Mesmer, 1766). According to Mesmer, the configuration of the planets and gravitation significantly influence the human body, conditioning both the health and the disease of the child, which is why he encouraged doctors to investigate such relationships.

However, “the term”animal magnetism” was not used in the dissertation, and the property that was described (“gravitus animalis”) subsequently shifted in Mesmer’s usage from a force that acts upon the body to a property of the body itself” (Lanska & Lanska, 2007, p. 303), and Mesmer declared that magnetotherapy did not require the application of magnets or magnetized objects, with the hand pass performed by the doctor being sufficient, given that the doctor was the true magnetizer. Mesmer thought that some energy must flow from the nerves of the fingers into the patient’s body, a vital energy more subtle than the mineral magnetism of magnets. From the use of magnets, Mesmer moved on to the use of magnetized objects and, finally, to the direct hand pass on the body of patients, based on the idea that the magnetic flux could have a direct effect from individual to individual.

As a result of his theoretical reflections and therapeutic practices, Mesmer (1779) presented 27 theses on animal magnetism, holding that (1) the entire physical universe is filled with a subtle flux that binds the heavenly bodies, the earth, and human beings, as well as human beings to each other, (2) the unequal distribution of the subtle flux in the body is the cause of disease, while health consists of, and is recovered, through the body’s rebalancing of the subtle flux, (3) the subtle flux can be transmitted, channeled, and stored by specific techniques, and (4) by such techniques, diseases and crises can be cured in patients. In line with what Mesmer argued in his doctoral thesis, he viewed animal magnetism as a natural phenomenon and, therefore, had to be scientifically addressed.

Despite its therapeutic success and high demand, especially among the more affluent social class who could afford Mesmer’s high fees, animal magnetism was strongly criticized and discredited (Crabtree, 2016). However, it spread rapidly throughout Europe (Ogden, 2018), including Germany (Gantet, 2021).

The reports on the phenomenon by a commission of inquiry set up at the behest of the Prussian government were favorable, and the German universities showed interest in animal magnetism (Ellenberger, 1970). In addition, the prevailing romantic trend in Germany in the 19^th century was very interested in phenomena related to animal magnetism −magic, somnambulism, clairvoyance, telepathy, the appearance of the dead, visio et actio in distans −i.e., a supernatural, metaphysical action that can influence something at a distance, without the need for direct contact−, somnambulic lucidity, and extrasensory perception, among others−, for they were believed to be the expression of communication between the human soul and a universal soul. Among other German doctors who cultivated animal magnetism, Dietrich Georg Kieser (1779-1862) and Justinus Kerner (1786-1862) strongly influenced the German philosopher Arthur Schopenhauer (1788-1860) (Schopenhauer, 1836/1998).

In 1809, Schopenhauer began his studies in medicine at the University of Göttingen, where he became aware of the possibility of reconciling physiology and philosophy (cf. Segala, 2024). Stimulated by the philosopher Gottlob Ernst Schulze (1761-1833), Schopenhauer decided to study philosophy at the University of Berlin, where he moved to in 1811 and remained until 1813 (Schopenhauer, 2022). In Berlin, in addition to attending the obligatory philosophy classes, Schopenhauer attended other classes in natural sciences and learned about animal magnetism with Dr. Karl Christian Wolfahrt (1788-1832), who was an important researcher of paranormal phenomena. In 1811, Wolfhart founded Askläepion, a journal that gave significant attention to animal magnetism. In 1812, he visited Mesmer in Frauenfeld and invited Schopenhauer to attend animal magnetism sessions (cf. Gwinner, 1862/2017).

Over the following decades, Schopenhauer maintained a strong interest in animal magnetism, following Armand-Marie-Jacques de Chastenet (1751-1825), Marquis de Puységur. Unlike Mesmer, who attributed magnetism to the subtle flux, Puységur believed that animal magnetism was linked to somnambulism −i.e., magnetic somnambulism− which was entirely influenced by the will of the magnetizer, a phenomenon of «believing-and-wanting.» This idea is clearly in line with Schopenhauer’s metaphysics since the idea of “believing and wanting” reflects Schopenhauer’s idea that belief and desire −as forms of the will− can shape experiences and even influence physical states, thus showing a parallel between Schopenhauer’s philosophy and Puységur’s theories.

Schopenhauer devoted his thought to the relationships between animal magnetism and his metaphysics of the will in three works:

1. The brief text «Suggestion of an Explanation of Animal Magnetism,» which was published after Schopenhauer’s death in the first volume of Manuscript Remains (Der handschriftliche Nachlass; HN1 hereinafter) by his disciple Julius Frauenstädt in 1864 (Schopenhauer, Vol. 1, 1864/1988)².

2. Section 6 «Animal Magnetism and Magic» of On the Will in Nature³ (Ueber den Willen in der Natur; WN hereinafter) (Schopenhauer, 1836/1998).

3. The chapter «An essay on the visions of ghosts» in the first volume of Parerga and Paralipomena (PP1 hereinafter) (Schopenhauer, 1851/2021).⁴

These three writings show (1) that Schopenhauer was interested in animal magnetism before writing his major work, The World as Will and Representation (WWR hereinafter)⁴ (Schopenhauer, 1819/2019), and (2) that his ideas about this phenomenon were already clear to him from his youth, and he went deeper into them throughout his life. Therefore, between these three works, there are elements of continuity and complementarity regarding animal magnetism.

Starting from Schopenhauer’s assertion that the world is will and representation, one could say that animal magnetism is will and representation; that is, animal magnetism is both a direct manifestation of the will and an objectification of the will in our nervous system. Therefore, animal magnetism can and should be approached from metaphysical and physiological perspectives.

This article aims to expose that, according to Schopenhauer, the phenomenon of animal magnetism requires the activity of the nervous system as much as the action of the will. The relevance of this demonstration comes from the lack of sufficient studies regarding the crucial role of physiology in the manifestation of certain phenomena, such as animal magnetism in Schopenhauer’s philosophical works.

2 Metaphysics and Nature in Animal Magnetism According to Schopenhauer

In «Suggestion of an Explanation of Animal Magnetism,» Schopenhauer presents the foundations of his conception of animal magnetism:

1. Johann Christian Reil’s (1753-1813) hypothesis on the opposition between the cerebral and ganglion systems.

2. The correspondence brain-knowledge and ganglion system-will.

3. Time and space as principium individuationis −i.e., the principle that explains how individual beings are distinct from one another, determining their unique identity− and about the objectification of the will, i.e., the world as representation −i.e., the phenomenon: what we can observe or experience−, not to the will −i.e., the noumenon: the reality in itself that exists beyond what we can experience or understand−.

4. The direct relationship of the ganglion system to the will, not to the representation.

5. The absolute freedom of the will with respect to representation, i.e., with respect to the principium individuationis.

6. Magnetizing is a direct material abolition of material isolation from itself in every individual and the consequent freedom of consciousness from the limitations of individuality.

7. The shifting of the consciousness −which is not subject to the principium individuationis− in the solar plexus −which is a complex network of nerves located behind the stomach and near the diaphragm that acts as a central hub for autonomic functions− and, therefore, the freedom of the consciousness from the limitations of individuality −which explains that the somnambulist, i.e., the magnetized, “knows just as well what goes on in other individuals and even at a great distance as what occurs in himself” (HN1, § 502) (Schopenhauer, 1864/1988, p. 372 [author’s translation])−.

8. The predominance of the ganglion system over the brain in the phenomenon of animal magnetism.

9. The abolition of the isolation of individuals −not the abolition of the principium individuationis− in the case of the magnetized.

10. Animal magnetism is a way of understanding the secret workshop of the will.

Schopenhauer develops these ideas in WN, where he offers a synthesis of his fundamental metaphysical ideas outlined in his first edition, WWR (Schopenhauer, 1819/2019): the identification of the will with the Kantian noumenon and the identification of the world −i.e., the totality of the physical universe, with its constitutive attributes of space, time, and causality− as representation −i.e., what Immanuel Kant (1724-1804) called phenomenon− (Schopenhauer, 1819/2019) (cf. . Magee, 1997).

For Kant (1787/2007), we can never know the noumenon directly. Only the phenomena are shaped by our senses and understanding. Schopenhauer, however, argues that the noumenon is not a vague, unknowable entity but is, in fact, the will −which is an irrational, blind force that underlies all existence− (Schopenhauer, 1819/2019). According to Schopenhauer, while the world as we perceive it is merely a representation −that is, a construct of our mind−, the true essence of reality −i.e., the noumenon− is this primal will (Schopenhauer, 1819/2019). This aligns with Kant’s view that our mental faculties structure the world. However, Schopenhauer gives it a more specific metaphysical interpretation, seeing the will as the fundamental force of both the physical world and human consciousness.

The will is the underlying noumenon that gives reality, albeit secondary and dependent, to the phenomenal. The will is the only thing that is real, subsisting, original, authentic, creative, and conditioning of knowledge. At the same time, phenomena are objectifications and mere dependent appearance and, from the plane of the inorganic to that of human consciousness and intelligence, subject to the laws of natural causality. This is so because the natural sciences “must at last come to a point where they finish their explanations, and this is precisely the metaphysical thing” (Schopenhauer, 1836/1998, p. 42 [author’s translation]), which gives them their foundation. In these ideas, Schopenhauer follows Kant’s teachings.

In WN, Schopenhauer links these metaphysical ideas to the findings of the physical sciences, confirming his metaphysics of the will, which is experienced inwardly by the person as belonging to his being and that is prior to intelligence. According to Schopenhauer (1836/1998), the findings of the physical sciences −which study natural phenomena− refer to his metaphysics on the will −i.e., the Kantian thing-in-itself−, and natural sciences and metaphysics converge, as if destined to do so, at a meeting point (Schopenhauer, 1836/1998). In this regard, physiology occupies a privileged place among the sciences concerning Schopenhauer’s metaphysics of the will.

At the beginning of section 6 of WN, Schopenhauer makes an essential distinction between the active and passive part of the phenomenon of animal magnetism. The active part of animal magnetism is its metaphysical or noumenal dimension. For Schopenhauer, this active part is the will, which is the immediate and direct agent cause of animal magnetism in human beings. Schopenhauer (1836/1998) devotes section 6 of WN to expounding this idea.

(…) the will, which I have established as the thing-in-itself, the only real thing in all existence, the nucleus of Nature, starting from the human individual, in animal magnetism, and above it, accomplishes things which cannot be explained according to the causal connexion, that is, according to the law of the course of Nature, and which it goes so far as to suppress, in a certain way, this law, exercising an effective actio in distans, thereby showing a supernatural, that is, metaphysical, dominion over Nature. I do not know what more reliable confirmation I can hope for for my doctrine. (p. 156)

As for the passive part, Schopenhauer refers to Reil’s hypothesis on the opposition between the cerebral system and the ganglion system, about which he says only that “it was used as an explanatory principle” (Schopenhauer, 1836/1998, p. 150 [author’s translation])⁵. The passive part of animal magnetism is, therefore, physiological in nature and relative to the phenomenal dimension of the world. In this connection, Schopenhauer resorts on a couple of occasions to Francis Bacon’s (1561-1626) assertion that magic −which for Schopenhauer is synonymous with animal magnetism− is empirical metaphysics (Schopenhauer, ^1836/1998). Schopenhauer says nothing more throughout the section of WN about this passive part of animal magnetism, focusing instead on the active part.

3 Animal magnetism from a metaphysical point of view

In the Prologue to the second edition of WN (1854), Schopenhauer (1836/1998) states he has arrived at the core of his metaphysics through the findings of natural sciences, in such a way that it is possible to establish a point of contact between the former and the latter. Like reality as a whole and in each of its phenomena, animal magnetism is a manifestation of the will, which is the same in all of them. Schopenhauer (1836/1998) considers that animal magnetism is the more reliable evidence for his metaphysics of the will, which exercises an actio in distans over nature (cf. Cartwright, 2020; Le, 2021; Segala, 2021).

While other authors explored explanatory hypotheses of a material nature for animal magnetism −e.g., physiological or related to the supposed cosmic ether⁶− Schopenhauer offers a metaphysical explanation. In his view, the agent operating in such a phenomenon is the will in and through the magnetizer, given that the magnetizer, as a material object of the physical world, is nothing but an objectivation of the will, according to Schopenhauer’s metaphysics: “that agent so profound which, proceeding from the magnetizer, produces effects apparently so contrary to the regular course of nature [is] nothing else than the will of the magnetizer” (Schopenhauer, 1836/1998, p. 151 [author’s translation]). So much so that manipulation is merely a means of fixing and shaping the volitional act and its direction (Schopenhauer, 1836/1998), and the signs, gestures, and words of the magnetizer, among others −i.e., what we might call «magnetic liturgy»−, are merely sensible expressions of the activity of the will.

Schopenhauer enthusiastically welcomed Kieser’s System des Tellurismus oder Thierischen Magnetismus; ein Handbuch für Naturforscher und Aerzte (Kieser, 1822) from which he extracts the fundamental idea that no magnetic act is effective without the will, whereas mere will without an external act can produce any magnetic effect. Manipulation only fixes and embodies the act and the direction of the will (Schopenhauer, 1836/1998). From Kieser’s System des Tellurismus, Schopenhauer (1836/1998) deduces the following:

(…) No magnetic act is effective without the will, and vice versa, the mere will, without an external act, can cause any magnetic effect. Manipulation seems to be nothing more than a means of fixing and at the same time giving body to the volitional act and its direction. (p. 152)

The idea that faith was the actual cause of the healing effects attributed to animal magnetism was consistent with this. In this regards, the forces of health and healing for Kieser “would be the manifestation of the divine in the human being. From the psychological point of view, which is fundamental to magnetism, such forces would be practically inexhaustible, since they proceed from will and faith” (Montiel, 2006, p. 149 [author’s translation]).

Schopenhauer (1836/1998) also alludes to a work on animal magnetism by the French mathematician Alexandre André Victor Sarrazin de Montferrier (Sarrazin de Montferrier, 1818). However, Schopenhauer only provides a brief literal quotation stating, along the vein of Kieser, that gestures, acts, words, and ultimately the magnetizing ritual are nothing more than an external, physical, and material mode of action −i.e., phenomenal objectification of the will−, of something that is essentially internal and immaterial −i.e., the will, which is of noumenal and objectifying nature−.

For Schopenhauer, a word spoken by the magnetizer to the magnetized acts with more energy than the will and that “manipulation and external action in general are properly an infallible mean of fixing the volitional activity of the magnetizer, because there is no place for external acts without any will, since the body and its organs are nothing more than a sensitization of it” (Schopenhauer, 1836/1998, p. 153 [author’s translation]). This would explain those occasions in which magnetization occurs without the conscious participation of the magnetizer’s will, which is why Schopenhauer says that Kieser recommends that during magnetization the magnetizer tries not to think or dialogue with the magnetized, trying to make everything happen unconsciously (Schopenhauer, 1836/1998).

The will is the agent −i.e., the efficient cause− in the phenomenon of animal magnetism that operates immediately without the need for physical intermediation, which is secondary. Nevertheless, it allows its action as a vehicle, given that the human being is a phenomenon and, as such, is affected by the phenomenal. It is precisely this capacity for immediate −and arguably all-powerful− action that the will can act on inanimate objects and even raise the dead. Schopenhauer resorts to the figure of Christ, apropos of The Revelation of Revelations: An Essay by the English mystical and visionary Christian theologian Jane Ward Lead (1624-1704), in which she affirms that Christ’s miracles were a manifestation of his will (Lead, 1701).

Schopenhauer was convinced that animal magnetism was a real phenomenon. An example of his conviction can be found in the note in which he refers to the demonstrations made in 1854 by the Italian mesmerist Antonio Regazzoni [Regazzoni of Bergamo] (†1870) in Frankfurt. Schopenhauer attended Regazzoni’s demonstrations and affirmed the undoubted authenticity of exercising the power of the will over people (Schopenhauer, 1836/1998).

However, medical doctors criticized Regazzoni’s seances in Frankfort and accused him of being a phony and a charlatan (cf. Gwinner, 1862/2017); this is the attitude that Schopenhauer calls «the skepticism of ignorance» in PP1. Schopenhauer also leveled this accusation of ignorance against the Franklin commission, which concluded that the existence of an animal-magnetic flux had not been demonstrated, and thus that it was useless and that its effects could be attributed to the imagination (Franklin et al., 2002)⁷. For Schopenhauer, that negative assessment of animal magnetism was out of prejudice due to the lack of knowledge that the will manifests in such a phenomenon.

Indeed, if the will is the noumenon behind every natural phenomenon, science cannot adequately assess it because metaphysics is beyond the domain of empirical science. Thus, it could be said that the Franklin Commission suffered from «metaphysical blindness,» which prevented its members, all of them eminent scientists, from discovering the true nature of animal magnetism: to be a representation −phenomenal expression− of the will −noumenal essence−. That is, to be a phenomenon of an essentially metaphysical nature. Schopenhauer also describes in PP1 the questioning of animal magnetism as ignorance −it must be understood that it is a metaphysical ignorance−, not as mere incredulity.

Even though, according to Schopenhauer, animal magnetism is a manifestative phenomenon of the will that does not need an external mode of action, it can benefit from one. In fact, according to Schopenhauer (1836/1998), animal magnetism implies breaking the boundaries and separating the magnetizer and the magnetized in such a way that both share thoughts, will, and acts. That, in turn, presupposes that the principium individuationis −i.e., time and space− is suspended and suggests that animal magnetism and magic are identical phenomena; this is an idea that he exposes in both WN and PP1.

In this connection, Schopenhauer (1836/1998) alludes to the «sympathetic cures» with which warts, fever, and other ailments were treated. Schopenhauer insists that such phenomena demonstrate that words and rites are not the fundamental elements; just the healer's sheer willfulness, the counterpart of the magnetizer, proves enough. Thus, animal magnetism, like sympathetic cure, acts without the need for material contact between magnetizer and magnetized. That is, animal magnetism acts in distans because of the power of the will.

Drawing on Kantian epistemology, Schopenhauer argues that the legitimacy of maintaining this conviction is based on the fact that we do not know the essence of reality, that is, noumena or things in themselves, but only their phenomena. If we knew things in themselves, “we would be entitled to reject a priori and unconditionally, therefore, all foreknowledge of the future, all apparitions of the absent or dying, or even of the dead, and all magical influences”⁸ (Schopenhauer, 1836/1998, pp. 161-162 [author’s translation]).

Given that we do not know things themselves, we cannot a priori reject animal magnetism. Schopenhauer quotes Kant’s Foundations of the Metaphysics of Morals: “Behind the phenomenon we must accept something else that is no longer a phenomenon, that is, the thing in itself” (Schopenhauer, 1836/1998, p. 163 [author’s translation]). Furthermore, the persistence of phenomena such as magic in all times and cultures is evidence of the human idea that there must be metaphysical causality in addition to physical causality. The explanation for phenomena that seem to go beyond ordinary knowledge, among which we find animal magnetism, is the omnipotence of the will itself.

In the case of phenomena such as magic, sympathetic healing, and animal magnetism, the physical is but a means for the expression of something whose true nature is metaphysical. As noted above, according to Schopenhauer, words, gestures, and rites are a mere phenomenal sign of something that is essentially immaterial. Moreover, the metaphysical will is communicable from individual to individual, transcending the material, for it is beyond time and space and, therefore, beyond material causality. The metaphysical will transcends the principium individuationis and allows for immediate communication between individuals, not mediated by time and space.

In this connection, Schopenhauer alludes to Mesmer, saying that he “at first attributed the success of his magnetization to the magnet or magnetic rod which he carried in his hands, instead of attributing it to his will, which was the real agent” (Schopenhauer, 1836/1998, p. 167 [author’s translation]). In the case of magic, sympathetic cure, and animal magnetism, the true agent is the immediate action of the will. As noted above, instruments, rites, and words as mediators of the will are merely accessories behind which the will operates immediately and directly. In turn, in support of his metaphysics, Schopenhauer echoes that “Mesmer at first attributed its action to the magnetic wand in his hand, explaining the wonder of animal magnetism by a materialistic theory, by a fine flux which penetrates everything, and yet despite this doctrine ceased to act with astonishing power” (Schopenhauer, 1836/1998, pp. 169-170 [author’s translation]).

Although Mesmer later realized there was no need for such mediating elements and that the will was sufficient to influence patients directly, he failed to see the metaphysical basis for that; this is what Schopenhauer saw. Animal magnetism, therefore, provides empirical evidence for Schopenhauer’s metaphysics of the will, and Schopenhauer offers a metaphysical foundation for animal magnetism.

Schopenhauer insists throughout section 6 of WN on this idea that the «magical force» resides in the will itself, which through the instruments merely “receives its direction and fixation in the corporeal world and enters into reality, and is therefore usually indispensable” (Schopenhauer, 1836/1998, p. 166 [author’s translation]). Schopenhauer’s aim seems to be none other than to show that animal magnetism is an empirical confirmation of his metaphysics. The will would operate as the first and most efficient cause of animal magnetism, as well as apparently also the only cause.

Nevertheless, the necessary participation of nature in the manifestation or objectification of the will allows us to maintain that matter is the material cause of animal magnetism as a phenomenon −for only the will is the noumenon−. The material cause of animal magnetism lies in the nervous system, specifically in the opposition between the cerebral and the ganglion systems.

4 Animal magnetism from a physiological point of view

Whereas in WN, Schopenhauer focuses on the will as a supernatural, metaphysical, direct, and immediate cause of animal magnetism, in PP1, he delves into the physiological hypothesis in his explanation of animal magnetism −as well as in the other phenomena to whose “family” it belongs−. Just as the will is the metaphysical dimension of animal magnetism, physiology is the phenomenal dimension of such a phenomenon, and it is necessary to attend to both these dimensions to giving a complete account of it since, as pointed out earlier, animal magnetism is will and representation.

As noted above, Schopenhauer stated in WN that the will is the active part of animal magnetism. In contrast, its passive part is of a physiological nature, and stated that this passive part was Reil’s hypothesis about the opposition between the cerebral system and the ganglion system.

5 Animal magnetism, dreams, and the «dream organ»

In PP1, Schopenhauer (1851/2021) reflects on animal magnetism in the context of two other phenomena: ghosts and dreams. Regarding dreams, he distinguishes characteristics perfectly attributable to animal magnetism. For example, (1) dreams are not simply a game of thought or mere images of fantasy, (2) in dreams, everything happens as in reality, with detail, exactness, and objectivity, and (3) the illusion create dreams is so strong that reality itself. In turn, these characteristics show that dreams −therefore, also animal magnetism− are a specific function of the brain and different from imagination and its reflection.

Like dreams, animal magnetism could be similar to madness: in these three phenomena, the absence of memory is essential, by which the person −asleep, magnetized, or alienated− is immersed in strange situations and performing actions that are out of the ordinary. Also, like dreams, animal magnetism could be explained by the state of the senses and the brain during sleep, that is, by the “suppression of the normal activity of the brain and senses [and has] its origin in the outward impressions of the senses [and] is not produced by the association of ideas [so that] the thread which the principle of sufficient reason put in our hand seems to us to be cut at both extremes, the inner and the outer” (Schopenhauer, 1851/2021, p. 253-254 [author’s translation]).

There must be some explanation for dreams and, by extension, animal magnetism. We believe that Schopenhauer’s hypothesis about the former applies to the latter. Schopenhauer puts forward this hypothesis in the following way. In the dream state, the external excitation through the senses and the internal excitation through the ideas are separated from the brain, which is the organ of representations. The physiological excitation of the brain must come from within the organism through two pathways: the nerves and the vessels. Schopenhauer alludes to a «life force» that restores the organism’s health during the dream state, thereby attributing to sleep a natural healing capacity −vis naturae medicatrix−. The effect of the process is “the restoration of clarity of consciousness” (Schopenhauer, 1851/2021, p. 256 [author’s translation]). This effect is precisely what also happens in the case of animal magnetism.

According to Schopenhauer, the brain “can be determined by excitations that come from within the organism to perform its function of intuiting figures that occupy space” (Schopenhauer, 1851/2021, p. 258 [author’s translation]). These internal excitations would be explained by the direct action of the will, which operates on its objectifications without the need for intermediary elements and without the resulting subjective experiences being distinguishable from those produced by stimuli through the senses.

For Schopenhauer, the physiological brain process underlying dreams is enigmatic and applicable to animal magnetism. In both phenomena, the brain activity is partial and limited since the brain is in a state of rest, a natural rest in the case of sleep, while an induced rest in the case of animal magnetism; hence, the name «magnetic sleep» is given to the latter. Underlying this process is the activity of a physiological structure, the «plastic nervous system» (Schopenhauer, 1851/2021). Schopenhauer alludes to Reil’s hypothesis mentioned in both «Suggestion of an Explanation of Animal Magnetism» (Schopenhauer, 1864/1988) and WN (Schopenhauer, 1836/1998) −i.e., the opposition between the cerebral system and the ganglion system−, which «served as an explanatory principle» of animal magnetism according to Schopenhauer and which constituted the passive part of this phenomenon. Therefore, in Schopenhauer’s view, Reil’s hypothesis seems to explain sleep and animal magnetism.

For Schopenhauer, dreams and imagination serve different functions in the brain. According to him, dreams arise from the unconscious, involuntary mind and are driven by the will, which operates independently of the rational, conscious mind. On the one hand, they do not involve the deliberate creative process associated with imagination. Instead, dreams emerge as an expression of repressed desires, fears, and instincts. On the other hand, imagination is a voluntary, conscious activity that involves the rational mind creating images, ideas, or scenarios (Schopenhauer, 1851/2021).

Schopenhauer believed that this distinction implies a physiological process because dreams are linked to physical states of the brain, such as during sleep when the body is inactive, but the mind is still processing. The physiological changes in the brain during sleep contribute to the involuntary, automatic nature of dreams, whereas imagination requires active mental engagement and higher cognitive functions, which are not bound to the same unconscious processes (Schopenhauer, 1851/2021).

Finally, that distinction between dream states and imagination is analogous to animal magnetism, which Schopenhauer saw as a process where unconscious influences, like the will, could affect others’ physical and mental states. Animal magnetism involves a transfer of energy or influence through unconscious, non-rational processes, much like how dreams and the unconscious mind work. Schopenhauer connected these phenomena because, in both dreams and animal magnetism, the will and unconscious forces play a key role in influencing the body and mind beyond the rational, conscious control of the individual (Schopenhauer, 1851/2021).

6 Schopenhauer’s hypothesis on the relationship between the cerebral system and the ganglion system

Reil proposed the term «vegetative nervous system» −also known as the ganglion system in Schopenhauer’s time− in 1807 and was convinced that the ganglia were independent sources of nervous power (cf. Oakes et al., 2016). Schopenhauer brings elements of his own to Reil’s hypothesis, stating that there is a fighting within the nervous system: “(…) what the ganglion system perceives is immediately combated by the brain. According to my hypothesis, this would be explained by the sudden change in the direction of the vibration of the brain fibers” (Schopenhauer, 1851/2021, p. 319 [author’s translation]), which applies to animal magnetism. Likewise, according to his physiological hypothesis, Schopenhauer (1851/2021) states that the intuitions that the dream organ effect differ from the perception in the waking state −which is dependent on the brain’s excitement−.

That intuition is that of magic, with which he explicitly identifies animal magnetism and the proper way to the thing-in-itself −i.e., to the will−, which is outside of time and space −i.e., the conditions of the principium individuationis−. Above these conditions, the will knows no limits to its action, which would explain, as in the case of animal magnetism, the possibility of direct action between magnetizing and magnetized regardless of their spatial proximity or remoteness (Schopenhauer, 1851/2021).

What does it mean that the will, in the case of animal magnetism −among other phenomena− acts directly beyond time and space and, therefore, beyond phenomenal causality? Schopenhauer offers the answer, according to which the metaphysical or noumenal is operationally linked as a cause to the physiological or phenomenal (Schopenhauer, 1851/2021):

While one’s will, which is not fettered by any limit of individuation, acts directly and in distans on another’s will, it acts precisely for this reason on their organism, which is nothing but their spatially intuited will. If such an action, which has thus reached the interior of the organism, extends to its director and president, the ganglion system, and enters the brain by breaking the isolation, the brain will never be able to process it except in the brain, i.e., it will provoke intuitions exactly the same as those formed from the excitation of the senses, that is images in space, according to the three dimensions, with movements in time, according to the law of causality, etc., since both are products of intuitive brain function, and the brain can only speak its own language. (p. 327 [author’s translation])

Schopenhauer seems to implicitly distinguish between the first cause and second instrumental cause in the case of animal magnetism, assuming the relation that theoretically exists between one and the other −i.e., that the first cause produces an effect by its activity and that the second instrumental cause depends on the first one and is subordinate to it−. Although the will is the principal efficient cause of animal magnetism −as it is of all natural phenomena− because it manifests the unlimited freedom of action of the will, the will must act phenomenally in the world. After all, the world is the objectification of the will (Schopenhauer, 1819/2019). Although Schopenhauer does not use the expressions «first cause» and «second cause,» these expressions would apply to the will and the psychophysical organism, respectively, concerning animal magnetism: the will would be the first cause of a noumenal nature −or as Schopenhauer calls it, the primum mobile−, and the organism would be the second instrumental cause of phenomenal nature that would operate, according to the hypothesis held by Schopenhauer, through the sympathetic or ganglion system.

It must be kept in mind that although the phenomenon is the representation of the noumenon in our brain, it is also the objectification and materialization of the will in nature, in the realm where the laws of time, space, and causality govern. This second instrumental cause of animal magnetism resides within the organism, “where some strange modification is produced which acts upon the brain using the vegetative nervous system, already related to the cerebral system, that is, using the sympathetic nerve and its ganglia” (Schopenhauer, 1851/2021, p. 297 [author’s translation]).

According to Schopenhauer (1851/2021), the will exerts a magical action on the phenomenal, which “is confirmed, legitimized by animal magnetism. However, the will −noumenal, supernatural− never acts in the world without natural causality −phenomenal, natural−, as Schopenhauer states in Chapter 4 on physical astronomy in WN:”wherever there is causality there is will, without the latter ever acting without the former” (Schopenhauer, 1836/1998, p. 145 [author’s translation]).

In addition to the distinction between the first cause −the will− and the second instrumental cause −the nervous system− the distinction between efficient, formal, final, and material causes can be applied to the role of the will and the nervous system in animal magnetism. The will would be its efficient cause −since will creates or generates the phenomenon−, its formal cause −insofar as will makes the phenomenon as it is−, and its final cause −insofar as the phenomenon is nothing but a manifestation of the will, a free expression of itself for itself−. Physiology, which links the world-as-will and the world-as-representation, would be the material cause of animal magnetism: “(…) since matter is the visibility of the will, and every force in itself is will, no force can appear without a material substratum” (Schopenhauer, 1819/2019, Vol. 2, p. 339 [author’s translation]). Although for animal bodies, “will itself is considered as representation, and therefore shown in the brain under the forms of space, time, and causality, that is, the mere sensitization, the objectification of the will” (Schopenhauer, 1836/1998, p. 101 [author’s translation]), the material cause belongs to corporeal beings as phenomena subject to natural laws −not to noumenon, which is essentially non-corporeal−.

Interestingly, Schopenhauer does not ask why some people cannot be magnetized. Is it a conflict of wills −the will in the magnetizer and the will in the magnetized? However, how could the will desire two contradictory things simultaneously in that case? Moreover, why would one will dominate over the other? Is it because of the difference in the force of the material cause between the magnetizer and the magnetized, a difference which phenomenally conditions the force of the will? Is the difficulty or even impossibility of magnetizing certain people a limitation in the power of the will over their phenomena? Curiously, Schopenhauer does not deal with these questions, any more than he does not cite significant works on animal magnetism that were published until 1854 −the year in which the 2nd edition of WN was published⁹−. For example, he did not cite Scottish physician James Braid (1795-1860), the father of modern hypnotism (Braid, 1843)¹⁰.

7 The «dream organ» and its role in animal magnetism

Sleep, second sight, ghost vision, clairvoyance, prophecy, and animal magnetism, among others, could be called the phenomena of altered consciousness and would be explained by the activity of what Schopenhauer calls the «dream organ,» which would be responsible for intuition independently of the impression of the external senses (Schopenhauer, 1851/2021). It must be supposed that the dream organ takes the place of the brain in the realm of the oneiric activity of the mind −which is the counterpoint to the brain’s representative activity−. However, the phenomena derived from the activity of the dream organ cannot be reduced to simple illusions or mirages −as we can think dreams would be, for example, when waking up−.

Likewise, just as in the case of deep sleep, when one wakes up, there is no memory of what was dreamed; in the case of magnetism, there is no memory of what has been experienced. Therefore, the state of magnetization is comparable to that of deep sleep. Hence, the magnetized may be compared to the somnambulist. Nevertheless, his somnambulism is not natural, as in the latter’s case, but induced somnambulism, that is magnetic somnambulism. Although it is not the most frequent, magnetic sleep can also be light −as can sleep− and in such a case, it will be possible to remember what has been experienced in such a state. What has been experienced in the magnetic state passes into waking consciousness as a memory (Schopenhauer, 1851/2021).

Therefore, the term «hypnotic» could refer to both the dream and the animal magnetizing states. In both cases, the organ at work is the dreaming organ, which, unknowable to Schopenhauer, does not know the limits of time, space, and causality that govern experience and knowledge in the waking state, that is, in ordinary consciousness.

The functionality of the dreaming organ is evidenced not only in the case of spontaneous or natural somnambulism but also in the case of magnetic somnambulism, which is proof of its comparability: “sleepwalkers artificially immersed in magnetic sleep perceive their surroundings and, if they become clairvoyant, even what is farther away” (Schopenhauer, 1851/2021, p. 263 [author’s translation]). What Schopenhauer says about the cataleptic state applies to the state of magnetization: “The brain seems to be in the deepest of dreams, that is, in absolute inactivity” (Schopenhauer, 1851/2021, p. 264 [author’s translation]). Therefore, the physiological cause of such phenomena does not reside in the brain but in another neurological structure that must be responsible: the sympathetic nervous system, especially the plexus solaris.

In this connection, Schopenhauer refers once again to Reil’s hypothesis, which, according to Schopenhauer, “is mainly based on the fact that almost all clairvoyant somnambulists affirm that at that moment their consciousness has its seat in the hollow of the stomach, where their thoughts and perceptions are produced, as is generally the case in the head” (Schopenhauer, 1851/2021, p. 264 [author’s translation]).

However, that is not plausible to Schopenhauer because if the solar plexus −which is also known as the cerebrum abdominale− could perform the same functions of intuition and thought as the brain, the law that nature does nothing in vain would be invalidated, and thus call into question the functionality and importance of the brain concerning those functions. Thus, Schopenhauer explains the phenomenon of somnambulism −both spontaneous and induced− in the partial activity of the brain, not in its replacement by the solar plexus. The brain is not inactive in the state of somnambulism but partially active, allowing the right direction of the sleepwalker’s steps, eliminating reflection, doubt, and indecision (Schopenhauer, 1851/2021).

Let us recapitulate schematically: (1) the state of animal magnetization is comparable to somnambulism so that both are hypnotic phenomena; (2) the functionality of the individual’s actions is explained by the action of a unique perceptual organ, i.e., the organ of sleep. Based on the declarations of somnambulists, Schopenhauer (1851/2021) adds that the organ of sleep operates in the brain through intuitions coming from within the organism, specifically from the plexus of the sympathetic nerve.

In Schopenhauer’s (1851/2021) view, the intuitive experiences of somnambulists, both spontaneous and magnetized, are not sensory perceptions, but their perception is a direct real dream produced by the organ of dreams. The physical actions of the somnambulist, such as placing an object at the level of their abdomen to presumably perceive it through the solar plexus, are analogous to the hands of the magnetizer, which do not act physically. The real agent is the magnetizer’s will, which receives direction and determination through his hands. The understanding of the action of the magnetizer comes hand in hand with Schopenhauer’s doctrine that the body and the will are one, in the sense that the body is “the image of the will that is formed in the brain” (Schopenhauer, 1851/2021, p. 270 [author’s translation]).

In this way, Schopenhauer asserts that one can “deduce the nature of all perception produced in somnambulism, including outward and distant perception, and in general, all intuition generated through the dreaming organ [like] an action from within, probably exerted through the mediation of the ganglion system on the brain” (Schopenhauer, 1851/2021, p. 270 [author’s translation]). Here, too, Schopenhauer seems to be proposing that, in the case of these phenomena of non-ordinary consciousness, (1) the will operates as a first cause and the nervous system operates as a second instrumental cause, and (2) the will is the agent, formal, and final cause of the action, while the body is the material cause of the action.

Perceptions in the somnambulistic state are produced through the dream organ, being “the activity of the brain’s intuitive function, stimulated by INTERNAL, rather than external, impressions” (Schopenhauer, 1851/2021, p. 270 [author’s translation]). Now, “that such an impression, though it concerns external and distant things, can have an objective reality and truth is a fact whose explanation could only be sought by metaphysical means, that is, from the limitation of all individuations and the separation of the phenomenon, as opposed to the thing-in-itself” (Schopenhauer, 1851/2021, p. 271 [author’s translation]). Somnambulistic perception is qualitatively different from that of the waking state, as evidenced by sleepwalking experiences, especially the most intense ones.

As for the physiological process of sleepwalking, Schopenhauer states that it is difficult to explain. For this, it would be necessary to have a physiological theory of sleep, that is, to know (1) the nature of brain activity during sleep, (2) how it differs from the waking state, and (3) where its stimulation comes from and the initial determination of the process. He offers his hypothesis about the physiology of dreams, which would explain the liveliness of «dream intuition» −i.e., perceptions in the state of dreams and magnetization− and which includes the following elements:

1. During sleep, the brain’s excitation for the intuition of forms comes from within; such an action must come in an opposite direction to the usual one, which is the pathway of the sensory nerves to the brain.

2. Therefore, the excitation of the brain’s fibers takes an opposite direction to the usual one −i.e., the antiperistaltic movement−.

3. White myelin would work instead of cortical gray matter and vice versa.

4. Thus, this would explain the lack of memory in the somnambulist in the waking state due to the conditioning caused by “the vibration of the brain fibers in the opposite direction, which consequently suppresses all traces of the previous one” (Schopenhauer, 1851/2021, p. 272 [author’s translation]).

It is through the activity of the dreaming organ that intuition is possible in the phenomena of somnambulism, clairvoyance, second sight, and visions. Now, for Schopenhauer, it is a fundamental truth that magnetic sleep is an intensification or incomparably deeper sleep than the natural, whose healing effect consists of an intensification of the natural healing power of sleep −that is, the healing effect of animal magnetism is nothing other than the healing effect of nature itself−. In this connection, the opposition between the cerebral and the ganglion systems plays a fundamental role: the magnetization action consists of suspending animal functions by diverting the vital force from the brain to the sympathetic nerve and its ganglia.

According to Schopenhauer, the positive current of the vital force, insofar as it is the will of the magnetizer, would exert its power over the brain of the magnetized, directing the vital force of the magnetizer to their sympathetic nerve −i.e., the area of the solar plexus−, from where it would return to the magnetizer’s brain, in whose experiences the magnetized would participate. Schopenhauer (1851/2021) makes this possible because, in the case of animal magnetism, the distance between the magnetizer and the magnetized is suspended, given that the will is not subject to time and space. However, once again, it seems that we are faced with the opposition between the first cause −the will, noumenon− and the instrumental second cause −the nervous system, phenomenon−, given that to exercise, express its power over natural reality −that is to objectify itself in it−, the will needs the participation of matter and its laws.

8 Conclusions

Animal magnetism attracted Schopenhauer’s interest as phenomenal, natural evidence for his metaphysics of the will. In turn, his metaphysics of the will revealed the true nature of animal magnetism. Animal magnetism is a phenomenon that could be approached from two points of view: natural and metaphysical. From a metaphysical point of view, animal magnetism is an objectification of the will. As a natural phenomenon, animal magnetism implies the laws of physiology −concretely, the opposition between the cerebral and the ganglion system hypothesized by Reil and which Schopenhauer applied to animal magnetism−.

The will can express itself freely without being conditioned by the limitations to which phenomena are subject, i.e., to time and space, which are principium individuationis. Likewise, the will acts directly on phenomena. Now, insofar as the will is not alien to the laws of phenomenal reality that it has created, its action is exercised through these natural laws, just as the action of the first cause is carried out through instrumental second causes. The will would be the first cause on which the instrumental second causes depend, and, therefore, in the last analysis, all the effects they produce.

In the case of animal magnetism, the distinction between first cause and instrumental second cause could be applied: the will would be the primary first cause, and the activity of the ganglion system would be the instrumental second cause. Likewise, efficient, formal, final, and material causality could be applied in a basic scheme to animal magnetism as a phenomenon both metaphysical and physiological: the will would be the first, preeminent, efficient cause, formal cause, and final cause, while the nervous system would be the material cause −although understanding matter not as something external to the will, as if matter were something with an existence independent of the will, but as the objectification of the will−. In fact, as noted above, according to Schopenhauer, the will never acts in the world without natural causality.

The laws governing the phenomena of nature are not forces opposed to the original, free, and first causality of the will but complement it by its expression, manifestation, or objectivization in the physical universe. Similarly, the laws of physiology that explain animal magnetism from the natural point of view do not contradict the first and principal causality of the will but complement it. Otherwise, the will could not express itself in the natural plane. Direct contact, gestures, words, and the entire «magnetic liturgy» may not be essential for magnetization, but the ganglion system activity is.

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Notas

1. Contemporary hypnosis differs significantly from the classical 19th-century use and the 18th-century animal magnetism. Modern hypnosis is generally understood as a therapeutic technique that involves focused attention, relaxation, and suggestion, often within a clinical context and is largely framed by psychological and neuroscientific understandings. In contrast, as popularized by Franz Mesmer, animal magnetism involved the idea of an invisible "magnetic flux" influencing the body and mind. It was often viewed with skepticism in its time due to its mystical nature.

2. Schopenhauer wrote «Suggestion of an Explanation of Animal Magnetism» in 1815, that is two years after he published his doctoral dissertation On the Fourfold Root of the Principle of Sufficient Reason and three years before he published The World as Will and Representation.

3. In Schopenhauer’s lifetime, the first edition was published in 1836, and the 2nd edition was published in 1854.

4. The only edition in Schopenhauer’s lifetime was published in 1851.

5. Reil contributed significantly to the emergence of psychiatry and modern neurophysiology (cf. Bahşi et al., 2022) and explained animal magnetism as a phenomenon of splitting between the cerebral and ganglionic systems.

6. Schopenhauer alludes to Mesmer.

7. In 1784, the King of France, Louis XVI, created two commissions to investigate the scientificity of animal magnetism. The first commission, on March 12, was composed of the French physician Joseph Ignace Guillotin (1738-1814), the American scientist and politician Benjamin Franklin (1706-1790), the French astronomer Jean Sylvain Bailly (1736-1793), the French chemist, biologist and economist Antoine-Laurent de Lavoisier (1743-1794), the physician and botanist Antoine Laurent de Jussieu (1748-1836), and four professors of the Faculty of Medicine of the University of Paris. On April 6, the second commission was composed of doctors Poisonnier, Jussieu, Caille, De Mauduyt, and d’Andry, members of the Royal Society of Medicine (Cfr. Kihlstrom, 2002).

8. In all verbatim quotations, italics and capital letters as in the original.

9. Schopenhauer took care of both the first and second editions (1836 and 1854, respectively) of On the Will in Nature, and his disciple Julius Frauenstadt took care of both the third and fourth editions (1867 and 1877, respectively).

10. Braid replaced the term «animal magnetism» with the term «hypnotism».