Mann started writing what was to become The Magic Mountain in 1912. It began as a much shorter narrative, which revisited in a comic manner aspects of Death in Venice, a novella that he was then preparing for publication. The newer work reflected his experiences and impressions during a period when his wife, who was suffering from a lung complaint, was confined to Dr Friedrich Jessen's 'Waldsanatorium' in Davos, Switzerland for several months. In May and June 1912 he paid her a visit and got to know the team of doctors who were treating her in this cosmopolitan institution. According to Mann, in the afterword that was later included in the English translation, this stay became the foundation of the opening chapter (Arrival) of the completed novel.
The outbreak of the First World War interrupted work on the book. The conflict and its aftermath led the author to undertake a major re-examination of European bourgeois society, including the sources of the wilful, perverse destructiveness displayed by much of civilised humanity. He was also drawn to speculate about more general questions surrounding personal attitudes to life, health, illness, sexuality and mortality. Given this, Mann felt compelled to radically revise and expand the pre-war text before completing it in 1924. Der Zauberberg was eventually published in two volumes by S. Fischer Verlag in Berlin.
His vast composition is erudite, subtle, ambitious, but, most of all, ambiguous; since its original publication it has been subject to a variety of critical assessments. For example, the book blends a scrupulous realism along with deeper symbolic undertones. Given this complexity, each reader is obliged to weigh up the artistic significance of the pattern of events set out within the narrative; a task made more difficult by the author's Olympian irony. Mann himself was well aware of his book's elusiveness, but offered few clues about approaches to the text. He later compared it to a symphonic work, orchestrated with a number of themes and, in a playful commentary on the problems of interpretation, recommended that those who wished to understand it should read it through twice.
Castorp's departure from the sanatorium is repeatedly delayed by his failing health. What at first appears to be a minor bronchial infection with slight fever is diagnosed by the sanatorium's chief doctor and director, Hofrat Behrens, as symptoms of tuberculosis. Hans is persuaded by Behrens to stay until his health improves.
During his extended stay, Castorp meets and learns from a variety of characters, who together represent a microcosm of pre-war Europe. These include the secular humanist and encyclopedist Lodovico Settembrini (a student of Giosuè Carducci), the totalitarianist Jesuit Leo Naphta, the dionysian Mynheer Peeperkorn, and his romantic interest Madame Clavdia Chauchat.
In the end, Castorp remains in the morbid atmosphere of the sanatorium for seven years. At the conclusion of the novel, the war begins, Castorp is conscripted into the military, and his imminent death on the battlefield is suggested.
Thomas Mann’s description of the subjective experience of serious illness and the gradual process of medical institutionalisation are of interest in themselves, as are his allusions to the irrational forces within the human psyche at a time when Freudian psychoanalysis was becoming prominent. These themes relate to the development of Castorp's character over the time span covered by the novel, a point that the author himself underlined. In the informative afterword written for the 1927 English translation, Mann states that "what [Hans] came to understand is that one must go through the deep experience of sickness and death to arrive at a higher sanity and health . . . ."
At the core of this complex work is an encyclopaedic survey of the ideas and debates associated with modernity. Mann acknowledged his debt to the skeptical insights of Nietzsche concerning modern humanity and embodied this in the novel in the arguments between the characters. Throughout the book the author employs the discussion with and between Settembrini, Naphta and the medical staff to introduce the impressionable Castorp to a wide spectrum of competing ideologies about responses to the Age of Enlightenment. However, whereas the classical bildungsroman would conclude by having "formed" Castorp into a mature member of society, with his own world view and greater self-knowledge, The Magic Mountain ends cynically, leaving him bereft of any real individuality, an anonymous conscript, one of millions, under fire on some battlefield of World War I.
Thus, The Magic Mountain contains many contrasts and parallels with the earlier novel. The established author Gustav von Aschenbach is matched to a young, callow engineer at the start of a humdrum career. The allure of the beautiful Polish boy Tadzio corresponds to the Asiatic-weary ("asiatisch-schlaff") Russian Madame Chauchat. The setting itself has shifted both geographically and symbolically; switching from the flooded and diseased Italian coastlands to an alpine resort famed for its health-giving properties, with the threat of a fatal cholera infection in Venice becoming the sanatorium's promise of a respite from, or a cure for, tuberculosis.
The Berghof patients suffer from some form of tuberculosis, which rules the daily routines, thoughts, and conversations of the "Half-a-lung club". The disease ends fatally for many of the patients, such as the Catholic girl Barbara Hujus whose fear of death is heightened in a harrowing Viaticum-scene, and cousin Ziemssen who leaves this world like an ancient hero. The dialogues between Settembrini and Naphta discuss the theme of life and death from a metaphysical perspective. Besides the deaths from fatal illness, two characters commit suicide, and finally Castorp goes off to fight in World War I, and it is implied that he will be killed on the battlefield.
In the above-mentioned comment Mann writes
The Magic Mountain, in essence, embodies the author's meditations on the tempo of experience.
The narrative is ordered chronologically but it accelerates throughout the novel, so that the first five chapters relates only the first of Castorp’s seven years at the sanatorium in great detail; the remaining six years, marked by monotony and routine, are described in the last two chapters. This asymmetry corresponds to Castorp’s own skewed perception of the passage of time.
This structure reflects the protagonists’ thoughts. Throughout the book, they discuss the philosophy of time, and debate whether "interest and novelty dispel or shorten the content of time, while monotony and emptiness hinder its passage". The characters also reflect on the problems of narration and time, about the correspondence between the length of a narrative and the duration of the events it describes.
Mann also meditates upon the interrelationship between the experience of time and space; of time seeming to pass more slowly when one doesn't move in space. This aspect of the novel mirrors contemporary philosophical and scientific debates which are embodied in Heidegger's writings and Einstein´s theory of relativity, in which space and time are inseparable. In essence, Castorp's subtly transformed perspective on the "flat-lands" corresponds to a movement in time.
The first part of the novel culminates and ends in the sanatorium's Carnival feast. There, in a grotesque scene named after Walpurgis Night, the setting is transformed into the Blocksberg, where according to German tradition witches and wizards meet in obscene revelry; also described in Goethe's Faust I. At this event, Castorp finally woos Madame Chauchat; their subtle conversation is almost wholly performed in French.
Another topos of German literature is the Venus Mountain (Venusberg) that also appears in Richard Wagner's opera Tannhäuser. This mountain is a "hellish paradise," a place of lust and abandon, where Time flows differently: the visitor loses all sense of time, and though he thinks his stay only lasts a few hours, when he finally leaves the mountain, seven years have passed. Also Castorp, who originally planned to stay for three weeks, leaves the Berghof only after seven years.
In general, the inhabitants of the Berghof spend their days in a mythical, distant atmosphere, full of references to fairy tales and sagas: The x-ray laboratory in the cellar is compared to the Hades of Greek mythology, where Medical Director Behrens acts as the judge and punisher Rhadamanthys and where Castorp is but a fleeting visitor, like Odysseus. Behrens also compares the cousins to Castor and Pollux, Settembrini compares himself with Prometheus. Frau Stöhr mentions Sisyphus and Tantalus, albeit confusedly.
The culmination point of the second part of the novel is perhaps the - still "episodic" - chapter on Hans Castorp's blizzard dream (in the novel simply called "Snow"), where the protagonist gets into a sudden blizzard, beginning a death-bounding sleep, dreaming at first of beautiful meadows with blossoms, and of loveable young people at a southern seaside; then of a scene reminiscent mainly of a grotesque event in Goethe's Faust I ("the witches' kitchen" , again in Goethe's "Blocksberg chapter"); and finally ending with a dream of extreme cruelty - the slaughtering and carnivoring of a child by two witches, priests of a classic temple. According to Thomas Mann's interpretation in the text, this represents the original, but deathly-destructive force of nature itself. Of course, finally Hans Castorp awakes in due time, escapes from the blizzard, and simply returns to the "Berghof". But rethinking his dreams he concludes for the moment that Because of charity and love, man should never allow death to rule one's thoughts. Hans Castorp soon forgets this sentence, so for him the blizzard-event remains a pure interlude. But for Thomas Mann himself the sentence (which throughout the whole novel is the only one in italics) remains important, and so he states it, for personal consequences and for his readers.
References to Grimm's Fairy Tales abound. The opulent meals are compared to the magically self-laying table of Table, Donkey, and Stick, Frau Engelhardt's persevering quest to learn the first name of Madame Chauchat mirrors the queen in Rumpelstiltskin. Castorp shares his first name with Clever Hans, but also his naïveté, losing in the end what he earned in seven years when his formative process abruptly ends on the battlefield.
As to the magical number seven: Castorp spends seven years at the Berghof, the central Walpurgis Night scene happens after seven months, both cousins have seven letters in their last name, the dining hall has seven tables, the digits of Castorp's room number (34) add to seven, Settembrini's name includes seven in Italian, Joachim keeps a thermometer in his mouth for seven minutes, and Mynheer Peeperkorn announces his suicide in a group of seven. Joachim dies at seven o'clock. Even Castorp's parents die when he is 7.
In fact, music plays a major role throughout Thomas Mann's work (as in many novels of the poet, already in the Buddenbrooks, but notably in Doktor Faustus): in The Magic Mountain, the recently invented Edison grammophone allows the Berghof people to listen to, e.g., Aida's final duet with Radames from Verdi's opera, and to Schubert's multi-valent song "Der Lindenbaum" from the Winterreise, both full of mourning feelings in the view of death. Hans Castorp engages himself very much in such presentations. With the last-mentioned song of Franz Schubert on his lips, our protagonist is told to vanish on the battlefields of World War I . (This end of the novel is at the same time of parodistic character, concerning the romantic love for "death", see e.g. Richard Wagner's Tristan und Isolde. It may also contain some amount of self-irony, since the song is sometimes considered as typical for prewar Germany, whereas the novel was published during the Weimar republic, which was now strongly defended by Thomas Mann.)
In any case one can speak of Thomas Mann's novel as "music by words".
In a way, Hans Castorp can be seen as the incorporation of the young Weimar Republic: Both humanism and radicalism, represented by Settembrini and Naphta, try to win his favour, but Castorp is unable to decide. His body temperature is a subtle metaphor for his lack of clarity: Following Schiller’s theory of fever, Castorp’s temperature is always 37.6°C, which is neither healthy nor ill, but an interstage. Furthermore the outside temperature in Castorp's residence is out of balance: it is either too warm or too cold and tends to extremes (e.g. snow in August), but never normal.
His antagonist Naphta describes him as "Zivilisationsliterat". Mann originally constructed Settembrini as a caricature of the liberal-democratic novelist, represented for example by his own brother Heinrich Mann. However, while the novel was written, Mann himself became an outspoken supporter of the Weimar Republic, which may explain why Settembrini, especially in the later chapters, becomes the authorial voice.
Settembrini's physical characteristics are reminiscent of the Italian composer Ruggiero Leoncavallo.
In Mann's original draft, Naphta was not planned but was added later, while the Weimar Republic was threatened by radical ideologies from all sides, eventually leading to its failure. Hans Castorp famously tries to classify Naphta politically and comes to the conclusion that he was just as revolutionary as Settembrini--not in liberal, but in a conservative way. So he decides that Naphta was a Revolutionär der Erhaltung (revolutionist of conservation). This apparent oxymoron alludes to a heterogeneous movement of right wing intellectuals called the Conservative Revolution. The term, probably first adopted by Hugo von Hofmannsthal, was repeatedly used by Mann and is meant to be revolutionary in a reactionary sense: The movement was highly nationalistic and not only fought against the ideals of left-wing socialism, liberalism and enlightenment, but it also detested the lost Empire’s dull conservatism of the petty bourgeoisie and the aristocracy. The movement was somewhat elusive, flirting with every radicalism against established views. Thus, Naphta himself is conceived as a living contradiction in terms: An ex-Jewish Jesuit, anti-capitalist, hostile to modernity, freedom, individuality and progress, anarchic and theocratic. Possible inspirations for Naphta are Leon Trotsky and Georg Lukács.
Mynheer Peepercorn, Clavdia Chauchat's new lover, enters the Berghof scenery rather late; but he is certainly one of the most important persons of the novel. His behaviour and personality, with its flavour of importance, combined with obvious awkwardness and the strange ability never to complete a statement, reminds to certain figures in former novellas of the author (e.g., to Herr Klöterjahn in Tristan) - figures, which are, on the one hand, admired because of their vital energy, and, on the other hand, condemned because of their naivety. In total, this person represents the grotesqueness of a Dionysian character.
Peepercorn ends by suicide, also performed in a strange manner.
By Mynheer Peeperkorn the author of the novel simultaneously personalizes his rival, the influential German poet Gerhart Hauptmann, and even certain properties of Goethe (with whom Hauptmann often was compared).