A holiday snap of a picnic encapsulates the peculiarly ambiguous position occupied by Joseph Goebbels in the Nazi hierarchy. Taken in the summer of 1931, it shows Goebbels, his lover Magda Quandt and friends, together with a beaming Hitler, in what looks almost like a family gathering. The impression evoked by the photo is not altogether misleading. Apparently strongly attracted to Magda, Hitler approved her marriage to Goebbels a few months later, creating a triangular relationship that endured until the pair followed him in committing suicide in 1945. Hitler spent a good deal of time with Goebbels and his wife, not only in their various apartments (which he subsidised) but also in their summer homes, as well as on trips to the theatre and cinema and holidays together. In addition, as Goebbels reports in his diary, Magda often spent days, sometimes weeks, alone with Hitler as his guest. The Goebbelses’ five girls and one boy, all of them with names that began with the letter H, served Hitler as a substitute family. Against this background, there was a certain logic to the decision Goebbels and his wife took to murder their children when they ended their own lives. The only member of Hitler’s inner circle to take this route, he could see no future for himself without Hitler.

The photo captures a moment in the interwoven lives of the Nazi leader and the propaganda chief who spent much of his life courting and serving him. What it does not show is the distance between Hitler and Goebbels in matters involving policymaking and decision-taking. Hitler rarely took Goebbels into his confidence in important matters of strategy. Goebbels was not involved in the negotiations with conservative forces that led Hitler to power. Nor was he informed of the action that would be taken against the Sturmabteilung (the SA or “Brownshirts”), a paramilitary organisation promoting a vehemently ­anti-capitalist version of Nazism, when on 30 June 1934, the Night of the Long Knives, Hitler had its leaders seized and killed. Goebbels was not invited when in November 1937 Hitler presented his long-term strategies to the heads of the armed forces, and was taken aback when the Nazi-Soviet Pact was announced in August 1939. As the war turned against Germany, Goebbels – along with others in the Nazi hierarchy – began to think of negotiating a separate peace either with the Soviet Union or with the Allies. He attempted to persuade Hitler to explore these possibilities on several occasions; but while he feigned interest, Hitler did nothing.

For all the seeming intimacy of their personal relations, Hitler never took ­Goebbels seriously as a strategist or adviser. At no point did Goebbels occupy the pivotal position in the Nazi regime that he wanted and at times imagined he had achieved. That does not seem to have disturbed him greatly. As the voluminous diaries that are the primary source of Peter Longerich’s authoritative, absorbing and chilling new account of Goebbels’s life make clear, his primary motive was always to serve Hitler. If this meant accepting shifts in policy about which he was not informed and that he may not have approved, his devotion to Hitler was in no way diminished.

Goebbels’s reaction to the Night of the Long Knives illustrates the extent of this devotion. He used the bloodletting to advertise his hero worship of Hitler. In his diary he noted: “Strasser dead, Schleicher dead, Bose dead, Clausener [sic] dead. Munich 7 SA leaders shot . . . Frau Schleicher died too . . . Pity, but that’s how it is.” In a radio broadcast on 1 July, Goebbels eulogised ­Hitler’s savagery: “What the Führer does, he does completely. The same with this business . . . Nothing by halves . . . But anyone who consciously and systematically rebels against the Führer and his movement should be in no doubt that he is playing a risky game with his own life.”

This reaction represented something of an ideological shift for Goebbels. In his early years as an unemployed writer in the 1920s, he belonged in the radical German nationalist current that was embodied in the Brownshirts, which despised ­bourgeois values and favoured a long-term alliance with the Soviet Union against the western democracies. An admirer of Lenin, who called himself “a German communist” and wore a “proletarian” leather jacket, he worked for a time on a social drama (never completed) called The Struggle of the Working Class. By 1931 Goebbels had shed these “anti-bourgeois” attitudes (though he still sometimes described himself as a socialist). But if Goebbels moderated his anti-capitalism, it was only to give more virulent expression to his anti-Semitism, which pre-dated his connection with the future Führer.

As he appears in the pages of his diaries, Goebbels was bewitched by Hitler and identified wholeheartedly with his belief that Germany must be saved from destruction by malign forces. As Longerich writes: “Goebbels repeatedly seized the initiative to play a pioneering role in Nazi ‘Jewish policy’: in 1933 at the time of the Jewish ‘boycott’, in 1935 with the Kurfürstendamm riots, in 1938 when in the summer he tried to unleash a pogrom and a few months later when he played an active role in the Nov­ember pogrom, and finally during the war with his continuing efforts to make Berlin ‘free of Jews’.”

Bizarre love triangle: under Hitler’s watchful eye, Goebbels weds Magda, 19 December 1931, on the estate of her first husband in Severin, Mecklenburg. Photo: Ullstein Bild via Getty Images

Goebbels was aware of the fate that Hitler had decided for Europe’s Jewish population. A detailed entry in the diary for 27 March 1942 describes the policy of methodical extermination that had begun in occupied Poland, where bases had been established for gas vans and a camp with gas chambers was being constructed – actions that were carried out in conditions of strict secrecy. Writing in the diary at the time, Goebbels mused: “Later generations won’t have the drive and the instinct for this, so it’s good that we are being radical and decisive.”

By far the greatest part of this massive volume (over 700 pages of text and nearly 300 of notes) consists of retelling the narrative presented in the diaries. As Longerich’s critics have pointed out, this is an approach that risks endorsing a distorted perspective: Goebbels cannot help putting himself at the centre of events when he was, in fact, often on the margins. But Longerich – the author of a seminal work on the origins of the Holocaust and a revelatory biography of Himmler – is fully conscious of this danger. The chronological narrative he presents is interspersed with passages of analysis that deflate his subject’s pretensions to be a prime mover of events. As Longerich shows, Goebbels was not notably effective in shaping the public mood; his ­principal success was in constructing the media cult that surrounded the Führer. Much of his time as propaganda minister was spent trying to keep up with developments over which he had little or no control.

There is a larger problem, which Longerich cannot solve easily. In the diaries Goebbels is crafting an image of himself for posterity – a picture of himself as he would like to be seen. We can assess his record of events by comparing it with others that were produced at the time, and correct biases in the way he viewed himself by considering how he was perceived by others. But how can we know if his inner experience was as he represented it to be? How can we grasp what really moved him to act as he did?

The key Longerich chooses to unlock Goebbels’s life is a species of psychoanalysis. “This book,” he writes, “is the product of a double process: evaluating the diaries as a historical source for a biography, and interpreting them in the light of the author’s personality.” Goebbels’s personality, Longerich writes, was shaped by “an exceptional craving for recognition by others. He was positively addicted to others’ admiration.” Never ceasing to relish the fanfare with which the media (controlled by himself) greeted his every announcement, he satisfied “all the essential criteria recognised in current psychoanalytic practice as defining a narcissistically disturbed personality”.

It was this personality disturbance that led him to worship Hitler. Goebbels “needed constant praise from an idol to whom he completely subordinated himself. From 1924 onwards, this idol was Adolf Hitler. By constantly confirming Goebbels’s special brilliance, Hitler gave him the stability he needed to maintain control over his life, a stability otherwise lacking in this unbalanced personality.” At the end of the book, Longerich identifies the source of this personality malfunction in his subject’s earliest years: Goebbels’s narcissism “originated in his failure to develop independence at the ages of two and three; his dependence on his mother, the model of his future girlfriends and wife, lasted throughout his life”.

These are speculative claims, and not particularly convincing. Were all of the millions of Germans who worshipped Hitler and enthusiastically served the Nazi regime suffering from personality malfunctions rooted in early childhood? It is not necessary to engage in psychoanalytical speculation to identify reasons why they felt and acted as they did. One of the functions of Nazism was to act as a means of social advancement. Like many who made their way through the Nazi machine, Goebbels came from a modest background. He was born in 1897 in a small industrial town, his father a clerk in a wick factory while his mother worked on a farm. Diminutive in stature and afflicted from childhood with a club foot, he cut an unimpressive figure in his youth and early adulthood. By throwing in his lot with the Nazis, he achieved a style of life of which he could not otherwise have dreamed. The diaries are studded with gloating references to the shiny new cars and spacious apartments that his position in the party secured him. Goebbels also used his position to satisfy his sexual urges, having many affairs (including one with a Czech actress that threatened his marriage until Hitler intervened and ended the liaison) and as head of the German film industry, which he nationalised, extorting favours from numberless young women.

There can be no doubt that Goebbels made full use of the perquisites of power, so it is easy to explain his involvement with Nazism as being motivated by opportunism. Yet his hero worship of Hitler shows every sign of having been wholly sincere. If he gained material advantages, that was (in his view) right and proper: such benefits were deserved reward for his services to the Führer and the Nazi cause. In thinking in this way, he was in no way exceptional. Swaths of the middle classes seem to have seen nothing wrong in enriching themselves through the Nazi Party, and aspired to precisely the sort of life that he enjoyed.

Goebbels did not follow Hitler for motives of careerism, or out of any hidebound belief in duty. He was no more an example of what Hannah Arendt described as the banality of evil than was Adolf Eichmann. Arendt suggested that people get caught up in malign movements and perpetrate atrocious crimes unthinkingly. Goebbels’s diaries show he was proud of serving the Nazi state and believed in it to the end. In one of his last quoted contributions to the Reich’s military conferences, he says that if Hitler

were to suffer an honourable death in Berlin . . . at the latest within five years the Führer would have become a legend and Nazism a legendary movement because he would have been immortalised by his final magnificent actions and all the human failings for which he is now criticised would be swept away at a stroke.

Rather than suffering from any individual mental pathology, Goebbels held to a view of the world that he shared with much of the population. In the economic chaos after the humiliating Versailles treaty that concluded the First World War, there were millions like him in Germany. He welcomed the Nazi regime not only because it offered material benefits of various kinds but because it validated impulses that were curbed in the civilisation the Nazis set out to overthrow and destroy. The joy of a type of communal solidarity that was based on hatred of minorities; the pleasure of having these minorities in one’s power and subjecting them to persecution; the delirious sense of release that comes from surrendering personal judgement and serving an autocratic leader – these were satisfactions that Nazism, at its peak, provided not only for Goebbels but for a majority of Germans.

The most striking aspect of the persona that Goebbels composes in the diaries is that it doesn’t try to conceal traits that any halfway decent morality would condemn. He is not ashamed of the abject servility that he shows in relation to Hitler; he glories in it. He registers no flicker of remorse regarding the targets of Nazi terror: he crows over their fate. What liberal civilisation – with all its flaws – regarded as vices, he displays as virtues. The thoroughly repellent figure that emerges from the diaries is not simply Goebbels as he was in fact. It is Goebbels as he wanted to be. He actively embraced barbarism as a way out from the chaos of his time, and in this he was at one with multitudes of educated Europeans. Viewing him as the victim of a personality disorder is a way of denying a more chilling fact that his life reveals – the perilous fragility of civilisation.

John Gray is the New Statesman’s lead book reviewer

Goebbels: A Biography by Peter Longerich, translated by Alan Bance, Jeremy Noakes and Lesley Sharpe, is available now from The Bodley Head (£30)