Johann Georg Zimmermann’s Therapeutics of Solitude in the German Enlightenment

This essay charts the German eighteenth-century physician and writer Johann Georg Zimmermann’s monumental work on solitude. The essay draws on but also challenges recent historiography on two counts. First, it situates Zimmermann’s discourse on solitude in the context of the early modern cultura animi tradition, in which philosophy provided a cure for a soul perceived as diseased and perturbed by passion and desire. Placed in this context, solitude comes into view not primarily as a passive state of rest and tranquillity connected to the rural life, but as active, therapeutic and exercise-oriented work on the self. Second, it argues that Zimmermann also shaped his discourse in relation to the increasingly radical late eighteenth-century exploration of subjectivity and selfhood, an exploration that reflects the emergence of the modern conception of the unique individual and autonomous self.

In recent years loneliness has become recognised as an increasing public health issue connected to mental illness as well as to many life-threatening physical diseases. To fight what seems to be a rapidly expanding new epidemic, governments as well as NGO s have launched a number of initiatives of which the perhaps most radical example is the appointment of a minister of loneliness in Britain in 2018. This widespread concern has not gone unnoticed among historians. In the celebrated 2019 study A Biography of Loneliness: The History of an Emotion, Fay Bound Alberti convincingly argues that the almost exclusively negative concept of loneliness as social isolation was an invention of the late eighteenth and early nineteenth centuries, connected to modern industrial and capitalist society.1 Before that, loneliness was typically phrased in terms of solitude; that is, a chosen state of being alone connected to calm and peace of mind. One year later, in 2020, David Vincent developed a complementary argument in A History of Solitude.2 Accordingly, parallel to the modern epidemic of loneliness there is a revival of solitude that goes back to the second half of the eighteenth century and particularly to the extensive writings of the German physician and writer Johann Georg Zimmermann. Zimmermann criticised and challenged the Christian ideal of a hermit living in isolation with a concept of solitude as periods and moments of withdrawal, often to a quiet rural setting, fully compatible with and even pivotal to a life as a functional social being.
In this essay, I engage with this scholarly discussion on two counts. First, rather than composing a longue durée history based on reconstructions of lived experience in combination with conceptual analysis -as Alberti and Vincent do -I situate German discourses on solitude in the context of what historians of philosophy and science have referred to as the early modern cultura animi tradition, in which philosophy provided a cure for a soul perceived as diseased and perturbed by passion and desire.3 Through a detailed analysis and contextualisation of Zimmermann's discourse, solitude comes into view not primarily as a passive state of rest and tranquillity connected to the rural life, but as active, therapeutic and exercise-oriented culture of the soul. Second, I argue that although the cultura animi provided the underlying conceptual framework, Zimmermann's discourse also took shape in relation to the increasingly radical late eighteenth-century exploration of sensibility, subjectivity and individual selfhood. Thus seen, solitude provided a space for the exploration of the self and particularly for the fulfilment of the individual perfections associated with the genius.

Solitude as cultura animi and Spiritual Exercise
In the autobiographical Reveries of a Solitary Walker (Reveries du promeneur solitaire), published posthumously in 1782, Jean-Jacques Rousseau described himself as a social outcast who had withdrawn from the world to conduct a final investigation of his self.4 So here I am alone on earth, having neither brother, relative, friend, or society, but myself. The most social and affectionate of men was outlawed by unanimous agreement…. But I, detached from them and everything, what am I myself? This is what remains for me to seek.5 Rousseau proceeded by asserting that the chaos that had long ravaged his soul had subsided and left room for a tranquillity that now served as a starting point for methodical self-examination.
I will relate my thoughts precisely as they occur to me, and with as little connection as the ideas of yesterday have with those of tomorrow. But this will in turn result in a new knowledge of my nature and my temper through that of my feelings and thoughts, a knowledge of which my mind nourishes daily in the strange state which is me…. In some respects, I perform on myself the operation that physicians conduct on the air in order to know its daily state.6 Two years after Reveries of a Solitary Walker was published, Zimmermann commented on it in the second part of the monumental four-volume On Solitude (Ueber die Einsamkeit, 1784-85). Zimmermann, who was a prominent physician, argued that the work reflected Rousseau's deeply melancholic character. Tormented by illness, poverty and public ridicule, 'Rousseau fled people in the last years of his life' , believing that 'they all conspired against him and that all people were against him in a horrible way' .8 Withdrawing from the world, he found little consolation but bitterness, hatred and disgust. 'He always wants to be alone, but never enjoys the solitude. He returns from the world to his chamber, and is disgusted by everything he sees there' .9 At the same time that Rousseau was clearly 'not an example to be followed' , his melancholy in combination with an undeniably powerful imagination provided a moral example.10 One has never considered that this terribly melancholy book, and the Reveries of a Solitary Walker attached to his Confessions, are, at the foot of Rousseau's statue, a humbling and touching example of human weakness, and for all time a horrific evidence of how black and false even such a mind is facing solitude when sick…. Solitude causes resentment when one takes one's imaginations for facts, and when this delusion is not interrupted and when one is not led back by anyone.11 As Zimmermann saw it, Rousseau's autobiographical writings provided valuable warnings of how even the greatest of minds could be misled, corrupted and destroyed.
In the above discourse, Rousseau connected solitude to the methodological examination of the self. Zimmermann, in turn, considered Rousseau's reflections to be a failure so gross as to represent a cautionary tale. Underlying this disagreement was an unspoken understanding of the rationale for pursuing solitude, and the ways in which it should be exercised. While cultural historians have persuasively reconstructed the lived experience, conceptual meanings and, lately, the material and geographical settings of solitude, little has been said about solitude in terms of a methodological and rule-governed exercise or technology of the self.12 8 Zimmermann, Ueber die Einsamkeit. Zweiter Theil,189. 9 Zimmermann, Ueber die Einsamkeit. Zweiter Theil,197. 10 Zimmermann, Ueber die Einsamkeit. Zweiter Theil,194. 11 Zimmermann, Ueber die Einsamkeit. Zweiter Theil, Alberti's Biography of Loneliness is a good example of the attempt to reconstruct solitude and loneliness as lived experience. To start unravelling the questions of the exercise and technology of solitude, the case of Rousseau and Zimmermann illustrates two things. First, solitude was expected to perform specific tempering and regulating functions determined by a conceptual framework that early modern intellectuals sometimes referred to as cultura animi.13 At the core of the cultura animi was the assumption that the soul is diseased and perturbed by passions springing from misconceptions and ignorance, and that philosophy provides a cure in the form of cognitive exercises of temperance and control best performed in solitude. Second, and related to the first, solitude was not a passive state that just happened or unfolded in situations of peace and calm, but an active state that required motivation, preparation and systematic method. Situated in this context, Rousseau's failure was not only personal, but also, as it were, a failure in solitude. The problem was neither the withdrawal itself nor the subjection to method, but the inability to follow and exercise the method in such a way that it produced the tranquillity and temperance that it was supposed to yield. In other words, Rousseau did right in conducting an examination of the self in solitude, but fatally failed to follow the method, as he made the passionsthe root of disease and corruption -the very driving force of investigation rather than the objects of extirpation. The result could only be an uncontrollable increase of the very passions that ravaged and diseased the mind in the first place. And yet, even though Rousseau's fate was sealed, it nevertheless focus has been more on the literary context. provided a valuable moral example of how the greatest of minds could be misled, corrupted and destroyed if entering into solitude without the right constitution and proper preparation.

Zimmermann's Therapeutics of Solitude
Zimmermann studied medicine under Albrecht von Haller in Göttingen, where he defended his dissertation in 1751.14 The doctorate marked the starting point of an impressive career as a physician, culminating with his appointment as physician-in-ordinary to king Georg III in 1768. Zimmermann was an extraordinarily multifaceted person who, in addition to his role as a leading physician, was a prolific writer on various topics, corresponding with many of the leading intellectuals of his time.15 His complex and somewhat tormented personality fuelled his explorations of solitude.16 Zimmermann's writings on solitude far exceeded any previous attempts to address the topic, as they included Reflections on Solitude (Betrachtungen über die Einsamkeit, 1756) and Of Solitude (Von der Einsamkeit, 1773), as well as the four-volume On Solitude (Ueber die Einsamkeit, 1784-85).17 As scholars have pointed out, this is a highly complex body of work that cannot be easily compartmentalised. It spans cultural history, medicine, philosophy and literature, and is partly written as a personal, autobiographical document. This breadth corresponds with an equally complex analysis, wherein several hundred cases drawn from history, literature and medicine are discussed in their individuality. The solitude that Zimmermann describes can be desired or avoided by different people and for different reasons, have different causes and unfold in numerous ways, be beneficial or harmful, reinforced or treated in manifold ways.18 The research on Zimmermann is considerable. Whereas anglophone scholars have approached him in a fragmentary way, for instance, by viewing him as an early pioneer of the modern conception of solitude, the German scholarly discussion is more thorough and oriented towards the specific contexts of eighteenth-century German society, culture and intellectual and literary debate.19 For my purposes, Markus Zenker's study of Zimmermann's work has been particularly important. Zenker analyses Zimmermann's literary production as therapeutic writing that reflects a tormented personality at the same time as it takes form in relation to the anthropological turn and to the German Enlightenment at large.20 Mark-Georg Dehrmann's study of productive solitude is also significant here.21 Dehrmann addresses the apparently contradictory interpretation of the German eighteenth century as the century of friendship and of solitude, arguing that Zimmermann advocated a productive solitude in which periods of withdrawal went hand in hand with sociability. This essay, while indebted to both, draws mainly on recent research within the history of philosophy and science when analysing solitude as cultura animi in the sense of an exercise-oriented regimen of the mind. Taking this stance, the essay highlights and explores a context that has mostly been neglected in previous studies of Zimmermann. Before turning to Zimmermann, it is worth noticing that the cultura animi approach to solitude was not his own invention. On the contrary, when he wrote his works, the link between solitude and cultura animi had already been firmly established in some of the most canonical texts on the topic. Petrarch thus opens the very first chapter of The Life of Solitude (De vita solitaria) by wishing that men were concerned as much for the cultivation of their minds as of their fields and many less important things; for the human mind teems with errors like a fat field overrun with brambles and if these are not diligently uprooted and with studious toil cleared away, the fruit in both cases will equally perish with the flower.22 19 For a recent overview of the state of the field, see Zenker, Therapie im literarischen Text, 55-78. 20 Zenker, Therapie im literarischen Text, 1-18. The anthropological turn signifies a broad interdisciplinary philosophical, literary and medical interest in the human being and particularly the mind, which flourished in eighteenth-century Germany. To withdraw from political turmoil and worldly affairs did not itself solve the problem of the raging passions. 'What advantage is there in strolling through woods and what delight in sitting upon mountains, if wherever I go my mind follows me, the same among the woods as in the city' .23 Instead, one must turn the gaze inwards to the mind itself and actively wage war on the passions.
But when the sway of reason shall come to impose its restraint on the rebellious impulses of our spirit, then we shall begin to understand what a serious war it is and what a troublesome province, to exercise rule over our self…. We too have to expel vice from our borders, put our lusts to flight, restrain our illicit propensities, chastise our wantonness, and elevate our mind towards higher objects.24 Drawing on ancient and Christian sources, Petrarch tapped into the cultura animi when emphasising that the tranquil life in the countryside was not enough if it was not dedicated to the culture and cure of the mind.
A second case in point is Michel de Montaigne's essay On Solitude. Much like Petrarch had done, Montaigne argued that even though a tranquil environment is preferable, it has relatively little to do with true solitude.
That is why it is not enough to withdraw from the mob, not enough to go to another place: we have to withdraw from such attributes of the mob as are within us. It is our own self we have to isolate and take back into pos-session…. It is in our soul that evil grips us: and she cannot escape from herself: In culpa est animus qui se non effugit unquam. [That mind is at fault which never escapes from itself.] So we must bring her back, haul her back, into our self. That is true solitude. It can be enjoyed in towns and in kings' courts, but more conveniently apart.25 Since the soul is diseased and cannot flee itself, the only way forward is to withdraw into the self and, like a physician, examine the disease and prescribe a suitable treatment. To do this it was important to first make the proper preparations. Drawing on Seneca, Montaigne further argued that 23 Petrarch For Petrarch and Montaigne seclusion and withdrawal from social life and worldly affairs could certainly mitigate the impact of the passions. Yet, as Montaigne paraphrased Horace, since the disease is in the mind and the mind cannot escape itself, true solitude could only occur if the time in seclusion were actively devoted to examining and curing the mind of its distempers. Zimmermann drew heavily on Petrarch, and, as we will see, the conception of solitude as an active therapeutic regimen for a tormented mind ran throughout his writings on the topic. In the 1756 Reflections on Solitude he thus remarked that 'just as one cannot maintain the health of one's intellect in complete distance from the world, so little is it possible to get to know oneself and to live according to one's destiny, when one is constantly being carried away by the turmoil of the world' .27 True solitude, Zimmermann argued, was indeed a withdrawal, but a productive withdrawal into the self rather than into social isolation.
In the lonely shadow of the night we think of great decisions, we penetrate our innermost being, and get to know our needs, our mistakes, and the means to counter them…. What the night does in this case, the moderate solitude of which I speak does with better results.28 In the 1773 treatise Of Solitude, Zimmermann continued along this strand of thought, arguing that a philosopher, or as I prefer to express myself without any peculiarity, a friend of truth and virtue, seeks solitude, partly out of discontentment and disgust of the world, partly out of a desire to increase the knowledge and sense of the good and true of his mind and heart.29 To withdraw into solitude was indeed to devote time to the culture of the soul. 26 Montaigne, 'On Solitude,' 277. 27 Zimmermann, Betrachtungen über die Einsamkeit, 27-28. 28 Zimmermann, Betrachtungen über die Einsamkeit,28. 29 Zimmermann, Von der Einsamkeit, 30-31.
There one withdraws the spirit from the compulsion of the senses, there one takes wing, there one acquires the energy of each thought and conviction, with which one later opposes unreasonableness and its vices in the course of the world like a solid dike to the stormy sea. In solitude, the powers of the soul are most expanded, animated, sharpened and heightened.30 In the four-volume On Solitude, Zimmermann emphasised that there are different reasons why people withdraw into solitude: for some it reflected an inability to socialise, or a sense of disgust for social life or even a pathological melancholy character, and for others solitude represented an opportunity to attain peace of mind. Of these, it was no great secret where Zimmermann's own sympathy lay. 'The less a person needs and the more diligently he strives to discover sources of pleasure in himself, the more easily he separates himself from other people, and the more certain he finds true happiness' .31 As Zimmermann had pointed out in his earlier works, the problem was how to find this happiness through solitude. To succeed in this endeavour was a strenuous and risky business that required a sound mind from the beginning. In the second volume Zimmermann discussed in detail the dangers of solitude. Underlying the analysis as a whole was the assumption that solitude especially reinforces and magnifies the sensual and affectual qualities of the soul. Since passions and affects become more intense, 'solitude becomes all the more negative when one brings an army of vicious thoughts and desires' .32 For this reason different persons seek and react in different ways to solitude. Whereas the overly sensitive soul of a religious enthusiast may fall victim to delusions to the point of hysteria and madness, the one who is prone to melancholy will find only an escalation of sorrow and pain. In the third volume Zimmermann emphasised that he would 'undertake to recommend solitude only to those people to whom pleasures of the spirit, clarity of concepts, virtue and overcoming are still worth something' .33 For those with the right constitution solitude provides an efficient means to further strengthen these very qualities. 'All these necessary qualities of the soul, stiffness, determination and stoic rigour of character, are certainly much more easily acquired in company with oneself' .34 Rightly exercised solitude was an effective medicine for the mind and a powerful bulwark against all kinds of disasters and sorrows in life. In fact, pain and suffering could even be actively used as a means to enter into solitary self-examination, a path that is difficult but also rewarding. 'Desolate, dark and rough this way certainly is; but after an arduous ascent it leads to lofty resting places, to peaceful banks and into the clear air of heaven' .35 In this regard solitude is 'a school of human knowledge because it sharpens the observing mind; because after quiet deliberation, we always know the better what we are looking for in the world; and especially because in solitude we digest all our observations and remarks' .36 To observe and examine the self was for Zimmermann an active state that required time. 'Freedom and leisure are all that a mind needs that strives for activity in solitude. Leave him alone and all his powers will be activated' .37 With the devotion of time, truth will unfold as the result of continuous self-examination. While scholars have typically situated Zimmermann's work in the context of eighteenth-century idealisation of the rural life in the countryside, I have in this section highlighted the cultura animi as a considerable but hitherto overlooked context for how to understand solitude. Against this background, Zimmermann's apparently modern conception of solitude turns out to be firmly grounded in the ancient and early modern view of philosophy as an exercise-oriented work of the mind. If there is a space of solitude, it is indeed a mental rather than a physical space, created through active, devoted and persistent exercise.

From Ancient cultura animi to Modern Subjectivity and Selfhood
So far, I have situated Zimmermann's conception of solitude in the context of early modern philosophy as spiritual exercise. In this section I show that Zimmermann, while clearly shaping his analysis in relation to the cultura animi, also challenged this very framework by embarking on a more openended exploration of subjectivity and selfhood. In doing this he was but one of many intellectuals whose work reflected what scholars have sometimes referred to as the emergence of the modern conception of the individual, unique and autonomous self. In its classical form the cultura animi was highly regulated, with little room for exploration of individual differences and subjectivity. The diseases of the mind were universal, as was the therapeutic regimen through which it was 35 Zimmermann cured. In the late seventeenth century, it was this conception that natural law philosophers such as Samuel Pufendorf and Christian Thomasius connected to when discussing the duties towards the self. Drawing directly on Cicero's classical definition of philosophy as cultura animi, Pufendorf thus remarked that 'the cultivation of the mind [cultura animi], which all men are constrained to undertake' requires that the conclusions on matters which concern his duty be rightly reached, that his judgement and opinion of matters which commonly arouse his appetite be properly formed, and that the impulses of his mind be regulated and governed by the rule of right reason.38 Similar points were made by Thomasius, who also invoked Cicero when making the Delphic proverb 'Know thyself' into the very core principle of the duties towards the self.39 About the same time Gottfried Wilhelm Leibniz expressed similar ideas in his metaphysics of perfection.40 Accordingly, human beings are obliged to perfect themselves as much as possible cognitively and morally, thereby contributing to the fulfilment of God's great plan for the perfection of the universe. Leibniz shared the assumption that improvement was attained through systematic exercise of the mind; he also envisioned a continuous and steady ascent to ever higher levels of perfection. In the first decades of the eighteenth century the philosopher Christian Wolff drew heavily on Leibniz when making perfection the core principle of his whole philosophy. In the German Ethics (Vernünfftige Gedancken von der Menschen Thun und Lassen, 1720) he thus formulated the moral imperative 'Do what makes you and your state more perfect and avoid that which makes you and your state less perfect' .41 Far from being just an abstract principle, perfection for Wolff boiled down to regular spiritual exercises. In addition to practising mathematics and science one should structure the day around systematic and regular self-examinations, the purpose of which was to set daily goals, evaluate failure and progress and make adjustments and improvements.42 In the 1740s and 1750s the Wolffian philosophy of perfection was further elaborated and revised by Alexander Gottlieb Baumgarten and Georg Friedrich Meier. Whereas Baumgarten stressed the exercise of the mind as well as the use of literary technologies such as diary writing in Philosophical Ethics (Ethica Philosophica, 1740), Meier provided a much more elaborate account in the monumental five-volume Philosophical Ethics (Philosophische Sittenlehre, 1753-61).43 Relative to those of his predecessors, Meier's discourse was more extensive, more detailed and more oriented towards concrete exercise. The selfknowledge that Meier referred to revolved around systematic self-examination and was therefore not to be confused with the everyday experience of life.44 Regarding this knowledge, Meier probably drew directly on Wolff when urging his readers to 'make oneself a reasonable and virtuous plan for the whole day' , to 'often think of one's present state during the day' , and to end the affairs of the day in the evening by considering one's past life and especially the past day, and investigating how one has spent the time and what good one has done, where one has failed, how one could have done better, so that one becomes wiser and is better able to plan the next day and act accordingly.45 In connection to these recommendations, Meier also suggested the use of diaries, here again emphasising the difference between unsystematic daily reflections and 'the preparation of a reasonable and pragmatic history of one's own heart and life' . Such history, he further argued, 'must be a true portrayal In Meier's discourse the merely regulative features of the classical cultura animi have been expanded into a more open-ended exploration of the self. Human existence unfolds as a multifaceted unique event that can be colourfully depicted in histories of the human heart. This interest in the potential of the human heart did not take shape in a vacuum but reflects what scholars have referred to as the anthropological turn.47 The anthropological turn signified a broad and interdisciplinary interest in the human being as a complex whole. Characteristics included a tendency to combine scientific studies of the human psyche with biographical and fictional accounts. Often one and the same author contributed to and blended different genres and discourses. One of the most significant expressions of this eclecticism was the emergence of a new form of anthropology and empirical psychology based on systematic self-observations.48 In 'Reflections on the Various Methods of Psychology' ('Betrachtungen über die verschiedenen Methoden der Psychologie' , 1771) the writer and literary critic Christian Gottfried Schütz provided a detailed discussion of both the potential and challenges of self-observation as a scientific method within empirical psychology. Since the soul is at the same time 'an actor and a spectator; a circumstance which causes the greatest difficulty in psychology' it was crucial both to develop systematic methods and to exercise one's ability to apply these.49 The same year, Zimmermann's close friend 46 Meier, Philosophische Sittenlehre. Anderer Theil, 408. 47 The research on the so-called anthropological turn is extensive. the writer and pastor Johann Caspar Lavater published A Secret Diary of a Self-Observer (Geheimes Tagebuch von einem Beobachter seiner Selbst, 1771). In the work, which the editor situated in the context of 'sensibility writings and contributions to the history of the human heart' , Lavater accounted in diary form for his day-to-day struggle to lead the life of a devoted Christian. The book was a success and two years later he published the sequel, Unchanged Fragments from the Diary of a Self-Observer (Unveränderte Fragmente aus dem Tagebuche eines Beobachters seiner Selbst, 1773). In this collection of allegedly unedited fragments the exploration of subjective experience is often strikingly present.
When I woke up, I considered and examined the previous day. I scrutinised all situations in my imagination. How often did I have reason to blush! How completely differently we see and judge ourselves if we only look at ourselves with the eyes of an impartial witness. With this in mind, I wished to have more time and skill in drawing in order to be able to fix by means of drawings many situations in my life that can hardly be described in words.50 In the early 1780s the philosopher and writer Karl Philipp Moritz brought the exploration of subjective experience through systematic self-observations and extensive histories of the heart to a new level by founding the first journal of empirical psychology. In a prospectus published in 1782 Moritz remarked that 'from the combined reports of many scrupulous observers of the human heart could an experimental psychology emerge, which practical utility would exceed everything that our ancestors have achieved in this field' .51 When the journal was published the following year under the title Know Thyself; or, Journal of Empirical Psychology (γνωθι σαυτον oder Magazin zur Erfahrungsseelenkunde, 1783-93), it featured a vast number of often extraordinary and pathological cases combined with biographical and autobiographical histories of the heart and soul, diary notes and self-observations brought from philosophy and medicine but also from literature. marks many of the contributions. Be they on physical or mental illness, biographical and autobiographical accounts or simply detailed observations of everyday life, contributions typically captured, either through first-person perspective or through the gaze of the disinterested scientific observer, the very nuanced richness of the individual and subjective experience. The journal was important both because it promoted and spread the new branch of psychology and because it served as a hub for the community of intellectuals that took form in the wake of the anthropological turn.53 In their contributions to the journal, writers thus often referred to other intellectuals associated with the anthropological turn, including Lavater, Meier and Zimmermann. Sometimes excerpts from popular texts were also published together with written comments and analysis. A particularly striking example is here the discussion of Moritz's own four-part novel Anton Reiser: A Psychological Novel (Anton Reiser. Ein psychologischer Roman, 1785-90).54 The work, which is often referred to as the first psychological novel, constituted an autobiographical study of Reiser's development from childhood to adulthood. As such it displays what the literary historian Christina Fossaluzza has referred to as 'subjective antisubjectivism' .55 Fossaluzza convincingly argues that the cautionary story of Reiser's life as a struggle between exaggerated sensibility and attempts to subordinate this very force to reason and morality reflects what was, for the time, a typical tendency to both embrace and control subjectivity, preferably by subordinating it to a moral-psychological regimen and scientific scrutiny.
Zimmermann's work on solitude reflects the anthropological turn to the human psyche, the individual and to subjective experience. Over and over again he thus stresses that solitude must be approached and studied as a complex and multifaceted phenomenon that unfolds in numerous ways depending on the circumstances. There are indeed many pitfalls and dangers associated with solitude. When chosen for the right reasons, under the right circumstances and with the right constitution, however, it provided a ladder to ever higher levels of perfection. 'The human mind never sees the end of its investigations. Investigations are linked to observations, experiments to conclusions, and immediately one truth follows from another' .57 Over time, such methodological self-examination inevitably leads to a deeper and more perfect knowledge of the self. This passage again illustrates how solitude was an active state of selfexamination and self-knowledge. In contrast to the classical cultura animi, with its stress on regulation and cure of the passions, however, Zimmermann's discourse taps into the late eighteenth-century romantic image of solitude as the breeding ground of geniuses.
Solitude often alone awakens genius, through its inner strength, without any help from the Great, without any encouragement, and even with the poorest reward…. Zimmermann's connection of solitude to genius provides perhaps the most extreme expression of solitude as the exploration and perfection of subjectivity and selfhood.60 Whereas the cultura animi aimed at virtue in the sense of a state of calm and peace of mind acquired through exercise, the kind of solitude depicted here sees no further limit to human refinement and perfection.
What makes Zimmermann's discourse on solitude particularly interesting, but which previous studies have neglected, is the way in which it took form in relation to the cultura animi tradition while at the same challenging this very framework. Fuelled by the anthropological turn, the sensibility culture and the turn to subjectivity and selfhood more broadly, solitude was not only a matter of disciplining and purging the mind of the passions but also of cultivating and perfecting it to the point of realising the genius, be it in the form of the philosopher or the more sensitive poet and writer. That Zimmermann hovers between warning his readers to avoid exaggerated ambition and enthusiasm and expressing his own excessive enthusiasm for perfection and genius reflects this very complex relation to the cultura animi.
Zimmermann was, as we have seen, far from unique when shaping his discourse in the intersection between embracing and disciplining subjectivity. On the contrary, the kind of 'subjective antisubjectivism' that Fossaluzza refers to marked the anthropological turn to subjectivity and selfhood as a whole. Zimmermann was thus one of many late eighteenth-century German intellectuals -including Lavater, Moritz and many others -who struggled to navigate between the ideal of discipline and control of the affectual and sensual self and the view of this very self as the key to a fulfilling life. While some sought to check the sensual and affectual forces using the classical cultura animi, others adopted the gaze of the disinterested scientist who surveys the ebbs and flows of the mind without interfering. Both strategies bear witness to a tension within the larger processes of the emergence of modern society and selfhood. 60 Before addressing genius in relation to solitude, Zimmermann had elaborated extensively on the topic in volume 2 of Of Experience in Medicine (Von der Erfahrung in der Arzneykunst, 1764). Zimmermann here defined genius as 'a high degree of perfection of all cognitive faculties' . He further argued that genius differs depending on the proportions between the perfection of the intellect and of imagination. Philosophers and physicians thus rely more on intellect, and poets, on imagination. The late eighteenth-century interest in the individual and subjective self has attracted scholarly attention for decades. Whereas intellectual historians have ascribed Romantic and idealist philosophy an important role in the emergence of the conception of the modern autonomous self, historians of science, culture and literature have drawn attention to larger processes of secularisation, the emergence of a new middle class and the public sphere.61 Thus seen, the exploration of topics of sociability, solitude, selfhood and radical subjectivity reflected a new middle class in the making, a class who had grown up with and rejected what they perceived as the repressive features of both orthodox Lutheranism and Pietism and who now sought to carve out a more lifeaffirming alternative that was better attuned to a modern civic lifestyle. In this development intellectuals such as Meier, Moritz, Lavater and Zimmermann were important not only because they advanced new conceptions of selfhood, sociability and solitude but also because they communicated these -often by using the new infotainment genres of the public sphere -to a broad readership of middle-class men and women.62

Conclusion
Focusing on the monumental writings of the German physician and author Johann Georg Zimmermann brings greater nuance to the scholarly discussion of solitude. Zimmermann's discourse emerged directly from the context of cultura animi tradition, where solitude was firmly established as an inner state of calm, rather than an environmental setting. In contrast to the modern concept of solitude, where peace of mind is often depicted as the effect of tranquil surroundings, solitude was thus the result of active and regular therapeutic work on the self. Zimmermann was deeply indebted to this view of solitude, and he repeatedly underlined that solitude cannot be acquired solely through external means but that it requires a continuous and diligent effort. While Zimmermann clearly shaped his conception of solitude in relation to the cultura animi, he also challenged this very framework by depicting solitary work on the mind as an ascent to ever higher levels of perfection or even as the breeding ground of genius. Far from being original, this account reflects the anthropological turn towards the human soul and subjectivity as well as the larger underlying process of secularisation and the definition of a new middle-class identity. Ultimately, it is one among many early indicators of the emergence of the modern conception of the individual and autonomous self.
With one foot in the old world and the other in the new, Zimmermann produced a highly complex and extraordinarily sensitive analysis of solitude that, despite its early date, speaks to our society today. The modern obsession with individual self-realisation, driven and accentuated through a never-ending stream of therapies and self-help programs, mirrors the very ambivalence that we find in Zimmermann's discourse. On the one hand, the mind is diseased and in need of a cure in the form of various therapeutic regimens. On the other hand, these regimens further serve to realise our true and perhaps limitless inner potential. Exactly this tension, which seems to characterise the modern individualistic self, is strikingly present in Zimmermann's own vacillation between caution and enthusiasm. The promise of ascent toward perfection and fulfilment also feeds into a very modern sense of loneliness. For the expectation of fulfilling one's true potential, and the risk of failure that haunts it, can indeed be very lonely and fraught with isolation and anxiety.