The era from the late 1950s through the early 1960s saw the dismantling of century-old antipathies between the Catholic Church and the Social Democratic Party (Sozialdemokratische Partei Deutschlands; SPD) in the Federal Republic of Germany. The SPD was West Germany's second largest political party and the formal heir to the socialist movement of the second half of the nineteenth century. It was no coincidence that this purposeful diminution of hostilities came on the heels of intense partisanship and bitter rivalries between the SPD and its arch rival, the Christian Democratic Union (Christlich Demokratische Union Deutschlands; CDU). Created in 1945, the CDU was officially interconfessional, but both its party base and leadership remained overwhelmingly Catholic.Footnote ¹ But even as both parties traded volleys over questions of rearmament and the relationship between church and state in the Cold War battlefield of the early Federal Republic, a small but significant number of intellectuals, politicians and churchmen, some nonplussed by the intensity of the ideological fervour, began to enter into dialogue. They did so first quietly and then openly, and with those from what was often euphemistically called ‘the other side’.

For Catholic integralists and militant socialist freethinkers, signs of this rapprochement proved bewildering and distressing. For a small number of hardliners on both sides, it was easy to attribute this increased willingness to enter into dialogue to two landmark events which they viewed with suspicion. The first was the SPD's Godesberger Programme of November 1959, which called on the party to carry out something long seen as unthinkable and be open to a ‘partnership’ with the churches.Footnote ² The second was the Second Vatican Council from 1962 through 1965, which pledged a greater openness to the modern world and sought to let fresh air into what many had come to regard as a stuffy edifice in need of renewal.

It would be foolish to deny or even minimise the significance of both the Godesberger Programme and the Second Vatican Council. Their statements inspired and motivated, giving formal legitimacy to dialogue. But to a substantial extent they also merely codified intellectual and political transformations underway long before and continuing long after. In other words, the roots were deep. They had emerged out of lessons painstakingly wrested out of the Nazi era and the immediate post-war era, after brutal dictatorships, exploiting entrenched ideological and social fissures both within and between the parties, had seized power and systematically eliminated opposition. Dialogue was given a new urgency because of the CDU's electoral triumphs of the 1950s and a decade later because of the SPD's increased share of the vote in national elections. By the federal elections of 1965 the SPD had seen its percentage of the vote rise to 40.1 per cent, a nearly eight point increase from its nadir in 1957.

Illustrative of this transformation was the political journey of the prominent and recently deceased Catholic intellectual and Westphalian native, Ernst-Wolfgang Böckenförde (1930–2019), who in 1967 at the age of thirty-seven formally joined the SPD, and who in the decades thereafter worked for its cause with the conscientiousness and rigor long ascribed to those from his region.Footnote ³ Böckenförde was no ordinary West German Catholic.Footnote ⁴ He had earned two PhDs, the first in law, the second in history. He had completed his Habilitation in 1964 with a magisterial work in constitutional history, Organisational Power under the Purview of the Administration: An Examination of Constitutional Law in the Federal Republic of Germany (Die Organisationsgewalt im Bereich der Regierung. Eine Untersuchung zum Staatsrecht der Bundesrepublik Deutschland) that almost immediately propelled him to a professorial chair in Heidelberg. Böckenförde would go on to enjoy a renowned career as a constitutional theorist, law professor and constitutional court justice from 1983 to 1996.

His journey to the SPD was also anything but ordinary. It was facilitated by conversations and correspondence with the party's intellectual and political luminaries, including its house lawyer, Adolf Arndt, its tactician and de facto leader, Herbert Wehner, and one of its chief ideologues, Willi Eichler. It was predicated on a transformation within the SPD and its growing openness to those of religious conviction. Böckenförde's path was, then, rarefied. It was not at all representative of those Catholics who simply switched votes or party affiliations with less reflection, lacking personal connections to the party leadership. Perhaps in keeping with this, Böckenförde himself later admitted that he had never been at heart ‘a 100-percent Social Democrat’.Footnote ⁵ He never fully embraced its position on abortion.Footnote ⁶ He remained a practicing and devout Catholic, one appreciative of its positions on the sanctity of life and its social teachings, limited in scope and long in ‘hibernation’ as they might have been.Footnote ⁷

This article examines the ideological and political transformations that allowed dialogue between Catholics and socialists to bear fruit. It begins by probing Böckenförde's frustration with the Catholic Church's scarcely-veiled identification with the CDU and showing how it led down a different path than that of many so-called ‘nonconformist’ left-wing Catholics who unlike himself harboured a deep sense of grievance against the political elite in the church.Footnote ⁸ It then analyses how Böckenförde slowly entered the orbit of the SPD as leaders like Adolf Arndt, Herbert Wehner and Willi Eichler were helping to bring about a profound ideological and political transformation. This article closes by examining briefly the significance of Böckenförde's activities on behalf of the SPD and the larger rapprochement between two once rival ideological and social milieu with sometimes hostile ideologies.

Böckenförde's path to the SPD was decisively shaped by his reflections on the modern state. His famous dictum stated that ‘the liberal secularised state lives from presuppositions that it itself cannot guarantee’.Footnote ⁹ Formulated differently: without democratic norms predicated on the willingness to accept that a political minority might someday become the majority (or vice-versa), a modern liberal democracy lacks the ethical foundation necessary for its stability and long-time survival.

As virtually every commentator on Böckenförde has recognised, Carl Schmitt – both through his writings and his personae – exerted a decisive intellectual influence on Böckenförde's conceptions of the state and constitutional theory from their first meeting in 1953 onward. Schmitt suggested topics that became the subject of his dissertation and Habilitation. In the words of Schmitt's biographer, Reinhard Mehring, Böckenförde was Schmitt's ‘most important post-war pupil, variously inspired by him, yet also being independent’.Footnote ¹⁰ Consistent with Böckenförde's independence of thought, Schmitt's influence on his mentee's reflections both on the state of German Catholicism in past and present and his aspirations of brokering a rapprochement between Catholics and the SPD was, in fact, not decisive.

This should not surprise: the two thinkers pursued different ideological and religious agendas. Though Schmitt was a fellow Catholic, one can describe him as a pious Catholic only with great difficulty. Schmitt accordingly identified himself as a jurist – and not as a Catholic jurist.Footnote ¹¹ In addition, Schmitt saw Catholicism as something of a relic; Christianity was destined to be secularised and, as Rainer Mehring has pointed out, Schmitt saw no chance for the ‘restoration of the old church’ in the post-war era.Footnote ¹² At best, one can see echoes of Schmitt in Böckenförde's understandings of intellectual and historical developments post-1789 and in particular the threats posed to the church by secularisation.Footnote ¹³ But such an analysis was in common currency and not the specific provenance of his mentor.

But, most significantly, many of Böckenförde's central concerns were not those of Schmitt. Böckenförde strove to put the Federal Republic on a more secure democratic foundation. His mentor, by contrast, was no staunch supporter of the fledgling republic. According to Mehring, it was a system that he ‘did not like’: as ‘a country without sovereignty’, it was of little interest to him.Footnote ¹⁴ And not least, Schmitt's past during the Third Reich was tainted, and Böckenförde knew it.Footnote ¹⁵ In 1961 Böckenförde published a landmark re-examination of German Catholicism in 1933, arguing in a pioneering article that support for National Socialism at the highest levels of the hierarchy and lay organisation was far stronger than the myths of resistance developed after 1945 would have it.Footnote ¹⁶ Böckenförde appended quotes from Cardinal Adolf Bertram, the church historian Joseph Lortz and the Benedictine abbot Ildefons Herwegen among many others. But at the behest of his philosopher friend, Robert Spaemann, Böckenförde inserted a lengthy footnote explicating Carl Schmitt's support for Nazism free of moralising undertones.Footnote ¹⁷ Schmitt was certainly no friend of the left and was a well-known defender of authoritarian emergency measures. Put in a position where he had to acknowledge his mentor's imperfect past while not jeopardising what had grown to be a deep working relationship, Böckenförde took pains to point out that Schmitt did ‘not actually belong to the Catholic ruling class’, and that he was not a representative of traditional natural law thinking.Footnote ¹⁸ Such quasi-exculpatory lines do not alter the fact that Schmitt provided little to none of the inspiration and sustenance for Böckenförde's quest to reconcile Catholicism and the SPD.

Böckenförde's reflections were far more in the spirit of post-war soul-searching, as many West German intellectuals, pondering the reasons for the collapse of the Weimar Republic, were striving to create a vigorous democratic culture capable of sustaining a new republic. Born in 1930, he was of the generation of intellectuals that some now refer to as the ‘generation of 1945’.Footnote ¹⁹ Like many in this cohort, he was preoccupied with the question of how to place the new Federal Republic on a democratic footing, a question not central to Carl Schmitt. How could liberal democrats in the Federal Republic create values and structures more likely to endure than those of their predecessors in the Weimar Republic and the German Empire? As a teenager, Böckenförde had been a witness to the collapse of the Third Reich and the rebirth of the German state and constitutional order.Footnote ²⁰ As a young student interested in law, he was driven by the question of how to develop more modern and era-appropriate forms of conservatism.Footnote ²¹

Unlike some of his fellow intellectuals, Böckenförde recognised the centrality of Catholicism to this process, even if German Catholics, historically a beleaguered minority, had cast a much smaller percentage of their votes to the Nazi party in federal elections from 1930 through 1933. His attention to the Catholic past and to the political ethos of German Catholicism stemmed first from the fact that he had been raised in a devoutly Catholic family.Footnote ²² His father was a high-ranking civil servant and intellectual who regularly read publications like the Rheinischer Merkur and the Catholic journal, Hochland.Footnote ²³ The latter was edited by Franz-Josef Schöningh, one of the co-founders of the Munich daily newspaper, Die Süddeutsche Zeitung.Footnote ²⁴ Schöningh was a distant relative, and over the course of the 1950s the ties between the young intellectual and the acclaimed publicist deepened. The former began to refer to the latter as ‘uncle’, and the two began addressing each other with the informal word for ‘you’ (du) instead of the polite terminology (Sie).Footnote ²⁵

But their recognition of the centrality of Catholic political attitudes to processes of democratisation was also driven by the obvious reality that Catholics – in a break from a century of historical precedent – were now at the helm of the fledgling Federal Republic. They also knew that the CDU enjoyed powerful support from the bishops and the church hierarchy in spite of the fact that it had opened itself up to both Catholics and Protestants. Seeing the ascent of National Socialism as the result of moral collapse and secularisation, many leading Roman Catholics, including founders of the CDU like the Berlin jurist, Hans Peters, sought to establish natural law as the fundamental principle of the moral and legal order in this process of reconstruction already in 1945.Footnote ²⁶ But these efforts unsettled the young Böckenförde, particularly when hardliners like the new Bishop of Münster, Michael Keller, threatened in early 1949 to urge Catholic leaders to withhold their support for the new constitution because of its lack of a provision guaranteeing the ‘right of parents’ to send their children to public schools segregated by confession.

Keller, in fact, proved unwittingly decisive – more so than Carl Schmitt – in shaping the trajectory of Böckenförde's writings on Catholicism. Böckenförde studied law at the University of Münster, the seat of Keller's bishopric.Footnote ²⁷ Keller was widely known for his uncompromising and highly politicised pastoral letters. He was apt to remind his flock of the issues at stake in upcoming elections, urging them to vote ‘Christian’: good Christians did not vote for the SPD or the Free Democratic Party (Frei Demokratische Partei; FDP). At the same time Keller repeatedly warned of the dangers posed by interconfessionalism, Protestants being more apt to quietly support socialist and liberal opponents, even though Protestant church leaders generally adhered to a strict code of political neutrality.Footnote ²⁸ In an address from 1957 he proclaimed that no true Catholic could vote for the SPD in good conscience.Footnote ²⁹ In a private letter to the Archbishop of Salzburg, he went even further, noting that it was his personal belief that it would be a form of ‘suicide’ for faithful Catholics to support the SPD.Footnote ³⁰

Keller's comments had come in response to a landmark decision by the German Constitutional Court over the validity of both publicly-funded denominational schools (Bekenntnisschulen) and the Reichskonkordat from 1933 signed by both Hitler's government and the Vatican. Its Article 23 provided specific guarantees for such schools and quickly became the focus of polemics not only about the church's role in politics but the church's historical baggage from 1933 and its responsibility for the consolidation of Hitler's dictatorship in the first half of the year. The court's decision from 1957 was a Solomonic masterpiece: it affirmed the validity of this treaty but maintained that public education under principles of federalism was a state and not a federal issue.

Böckenförde's interest in church–state relations was kindled not just by the polemics hurled in the protracted fight over the concordat.Footnote ³¹ It was also driven by his exasperation (Verärgerung) at Keller's proclamations against the SPD that had only grown in intensity during the election campaign of the summer of 1957, as well as his concerns about the genuine commitment of Catholic religious and political leaders to democratic values.Footnote ³² The budding public intellectual and scholar felt compelled to put pen to paper to warn against a development which in his eyes could only lead to a new Kulturkampf atmosphere which would ‘attack the fundamentals of our still very weak state order’ and cause the church itself to lose credibility and its potential to exert its own influence.Footnote ³³ That the ‘theological becomes the ideological’ is surely a ‘great temptation and danger’.Footnote ³⁴ ‘Yet I fear’, he wrote, ‘that the church will not notice that this article is not written against it but for it’.Footnote ³⁵

Indeed, implicit criticisms of Keller's positions underpinned Böckenförde's debut article. Solicited by Franz-Josef Schöningh, this was a set of reflections on the role of the church in a democratic society that appeared in Hochland shortly after the CDU's triumph in the 1957 election.Footnote ³⁶ Under the title ‘The Ethos of Modern Democracy and the Church’, Böckenförde argued that the insistence on upholding teachings and principles derived from natural law reflected a larger indifference to the proper forms of government.Footnote ³⁷ Roman Catholics could adapt to any form of state, be it democracy, monarchy or even dictatorship, so long as it was based on a Christian footing: decisive was only whether principles derived from natural law were likely to be upheld.Footnote ³⁸ This observation was obviously a criticism of what he perceived to be tight links between Christian Democracy and the church that politicians like Thomas Dehler or the political scientist Thomas Ellwein were excoriating as ‘clericalism’.Footnote ³⁹ In fact, allegations of Catholic ‘clericalism’ had proven polarising from the late 1940s onward, centred as they were on questions of church–state relations.Footnote ⁴⁰ But Böckenförde's article reflected deeper anxieties that the Federal Republic might also be a democracy without democrats and with fickle republican allegiances. It was driven by lingering fears about the ‘tyranny of the majority’.

Was the Catholic Church indeed truly committed to an ethos of democracy and willing to countenance minority rights? A landmark article published in 1961 and once again in Hochland hinted that this was not necessarily the case.Footnote ⁴¹ Titled ‘German Catholicism in 1933: A Critical Examination’, it put on display an array of terrifying quotations from cardinals, bishops, theology professors and lay presidents who in 1933 had enthusiastically exhorted their fellow Catholics to support and help build the fledgling Nazi state.Footnote ⁴² Why had they done so? Here, Böckenförde drew on the argument he had raised in his essay from 1957. They did so because Catholic loyalties to republican forms of government remained contingent on whether demands derived from natural law teachings could be realised. Long driven by a hostility to the secular, liberal state order that dated back to the French Revolution, Catholicism, according to Böckenförde, was in need of a certain ‘enlightenment’ – one that would allow it to achieve an unconditional inner affirmation of modern democracy lest the past be in danger of repeating. His concluding line left little to the imagination: ‘or can one seriously say that the positions and political principles which led to the errors of 1933 have been overcome in the German Catholicism of today?’

Böckenförde's solution? The church needed to abandon its dreams of using the political order to create a Christian state. It needed to assume a new role, what he called a Hüter- und Wächteramt, a watchtower from which it would seek to influence all political groups and parties in a bid to disseminate religious and moral values. The ecclesia was to stay out of political fights as much as possible, leaving this work to the faithful.

But precisely because of the lack of clarity given to this lobby function, this was a formulation easily prone to misinterpretation. Twelve years later he provided a fuller elaboration.Footnote ⁴³ The church's role was essentially negative: it was to speak out only against clear breaches of God's commands and even there was to admonish in the style of ‘thou shalt not’. The church was to remind the faithful to act and live for faith in the socio-political realm, to renounce self-interest, power and possessiveness and to call for justice, love of one's neighbour, and the general good. Did this mean that the church was now limited to an apolitical conduct? Not necessarily. Using Carl Schmitt's notion that what was understood as political necessarily varied according to the degree of intensity of ‘association’ and ‘disassociation’, Böckenförde noted that simple proclamations of Christian truths could and would be given political meanings. In certain contexts they would serve as challenges to the existing political order, as had been the case with Graf von Galen's sermons against euthanasia in the summer of 1941.Footnote ⁴⁴

In 1957 Böckenförde was not considering switching parties, but, clearly, these ideas were consistent with his eventual decision to join the SPD and to distance himself from the CDU.Footnote ⁴⁵ The church was not to bind itself to any one political party but to act as a guardian for all. It could serve as a lobby, but one that would issue entreaties to all parties. If the church was to seek to influence all parties, why did he over time put down roots in the SPD, a step that for most loyal Catholics in the 1950s and even early-to-mid 1960s would have been inconceivable?

Here, a comparison with so-called ‘Catholic nonconformists’ is instructive.Footnote ⁴⁶ Many of these frustrated Catholic left-wingers chose to step outside the world of organised Catholicism and its formal edifices like the Central Committee of German Catholics. Some like the writer Heinrich Böll offered bitter reflections on their marginalised status, Böll doing so in his acerbic novel from 1963, The Clown.Footnote ⁴⁷ Böckenförde, by contrast, never left the formal world of German Catholicism, even after he joined the SPD. It was he who helped ghost write a speech entitled ‘Peacemaking’, delivered by Chancellor Helmut Speech to the Katholikentag in Düsseldorf on 3 September 1982 amid the furore over Reagan's stationing of SS-20s on German soil.Footnote ⁴⁸ In other words, Böckenförde, in establishing powerful ties to the political and intellectual elite within the SPD, was accomplishing the opposite of the non-conformist Catholics: he was building bridges instead of scorching the earth.

But a rapprochement between Catholicism and the SPD was anything but a given in the immediate post-war era.Footnote ⁴⁹ As Stefan Berger has reminded us, the relations between socialism and religion had been fraught with ambiguity since the second half of the nineteenth century.Footnote ⁵⁰ On the one hand, a profound reserve in the party towards religion ran deep. There were few practicing Christians, Catholic or Protestant, in the highest ranks of the SPD during the Weimar era. In 1919 only fifty-three of 165 delegates could be considered religiously active; thirty-eight were Protestant, nine Catholic.Footnote ⁵¹ By 1928 that number had fallen further. Of 152 delegates, only nineteen were active religiously; ninety-eight described themselves as having no confessional affiliation (konfessionslos).Footnote ⁵² Until the proclamation of the Godesberger Programme in 1959, the SPD remained formally wedded to Marxism, an ideology draped in a militant secularism and anticlericalism. Religious freethinkers from the Weimar era despised the irrationality of organised era; Marxists in the party continued to see religion as the opiate of the masses and the churches as tools of the owners of the means of production.Footnote ⁵³ Because of this tradition, Catholic polemicists dismissed the SPD as embodying classical ‘materialism’ and enthralled to collectivist godless ideologies.Footnote ⁵⁴ Even well after 1959 Catholic integralists like Gustav Kafka in the Central Committee of German Catholics continued to question whether the SPD's transformation was genuine and not merely a smokescreen to dupe and attract religious voters.Footnote ⁵⁵

On the other hand, there had long existed a foundation for building bridges between the SPD and the church.Footnote ⁵⁶ Many early party activists could easily find common cause with Christian socialists and, from the Catholic side, with those genuinely committed to Catholic social teachings. The schism within the SPD during the closing years of the First World War led to the departure of those most hostile to the church, including many of its outright atheists, and their new home in the German Communist Party (Kommunistische Partei Deutschlands; KPD). To a certain extent, Christians and Social Democrats could cooperate over their anti-communism, even if their reasons for this antipathy diverged. The SPD supported the election of Wilhelm Marx in the elections of 1925 over the Communist leader, Ernst Thälmann. Most socialists could easily support a programme calling for tolerance for all religious persuasions. This meant that Catholic bridge-builders to the SPD were likely to most committed to an agenda of religious pluralism and aghast at voices of intolerance from within their own ranks.

But it was by no means guaranteed even in the 1950s that bridge-builders from socialism and Catholicism would find the way to each other. It took something else: the SPD's transformation from a narrowly ideological ‘milieu party’ with a once substantial but now shrinking base from the workers’ club, organisations and trade unions of the Weimar era to a genuinely moderate left-wing national party (Volkspartei) that appealed to men and women from all social classes, occupational groups and religious denominations. While Kurt Schmacher had attempted to open the party to the middle classes immediately after the war, his often blunt rhetoric proved a deterrent. So too did the fact that many SPD leaders after the war had been active in the SPD labour movement of the Weimar Republic. Having maintained their faith in it during the twelve years of dictatorship, they found it difficult to envision a party that outwardly departed from the traditions, identities and rituals of their formative years.

It took a new generation of leaders, some from bourgeois backgrounds, others astutely drawing lessons out of the party's failures between 1930 and 1945, to help steer a new course and transform it to a pragmatically reform-minded centre-left party which granted legitimacy to its political opponents. It also took new leaders with not just a far greater openness to religion but religious convictions themselves. While at work on this article in the spring of 1957 and as he began a doctoral programme in history in Munich under the direction of Professor Franz Schnabel, Böckenförde encountered one of these transformative leaders. This was the renowned Adolf Arndt, the SPD's brilliant bourgeois-born house lawyer, who had dominated the oral exchanges before the Constitutional Court in Karlsruhe in early June 1956 over the validity of the Reichskonkordat.Footnote ⁵⁷ Böckenförde attended a lecture of Arndt at the Technical University in Munich, where he spoke out against the ideological and political divisions still besetting West Germany. Arndt observed that the German parties increasingly resembled religious institutions: they were Weltanschauungsparteien whose platforms had become matters of faith. ‘A democratic party cannot turn its historically conditioned answers’, he stated, ‘into basic matters of faith’. His criticism was obviously directed at the CDU, which in his estimation threatened to degenerate into a ‘church party’ (Kirchenpartei).Footnote ⁵⁸ But he went further, claiming that the CDU's art of politics, however conducted ‘in the name of God’, was no longer used ‘in his service’.Footnote ⁵⁹

But Arndt's criticism was directed no less against his own party which still held on officially to doctrinal Marxism and by extension the anticlericalism that went along with it. Though half-Jewish and persecuted by the Nazis because of his status as one of mixed race (Mischling), Arndt himself was a devout Protestant, one transformed by the ideas of Karl Barth and the Barmen Declaration of 1934.Footnote ⁶⁰ Recognising that the churches and Christians had the duty to make public their message (Öffentlichkeitsaufgabe), Arndt took issue with the SPD's deeply rooted conviction that religion was to remain purely a private matter.

Arndt's criticisms of his own party were of course driven by considerations of political tactics. Without Catholic voters, particularly in the wake of the 1957 elections that had given the CDU an absolute majority for the first and only time in its history, the SPD would never be able to take over or share the reins of political power.Footnote ⁶¹ In fact, it took a series of electoral disasters – the national elections of 1953 and above all, the crushing defeat of 1957 in which the SPD received only 31.8 percent of the vote while the CDU/CSU received 50.2 percent – to drive this message home to the party faithful. But Arndt's critique also reflected genuine conviction born out of his reflections on the recent catastrophic past. Aware of illiberal currents within the SPD's own past, Arndt sought to allay doubts about the genuine commitment of Social Democracy to a democratic ethos. He pledged tolerance for different values – disagreeing with the position but not attacking the legitimacy of the person. At stake was the democratic substance of the republic – and to create this, democratic socialism and Christianity had to find grounds of compatibility. But this compatibility could only take place if both socialism and Christianity no longer saw themselves as all-encompassing ‘totalising’ ideological and religious doctrines, to use the phrase of Aline-Florence Manent, that aimed to subsume ‘the individual into the collective’.Footnote ⁶² Ideology and political mission thus had to be decoupled from each other.Footnote ⁶³

Though not persuaded by all of Arndt's arguments, Böckenförde described the lecture as having ‘reinforced’ his own resolve to work towards what became one of his fundamental goals – gaining the church's approval and recognition of a pluralistic society.Footnote ⁶⁴ Confirming Böckenförde's expectations that his article in Hochland would unleash a ‘small storm’, it was precisely this argument that unleashed tremors amongst concerned laity and clergy who perceived it as ‘rebellious’.Footnote ⁶⁵ It led Bishop Keller to engage in extensive conversations with his secretary, Hermann-Josef Spital, a curate in his early thirties who would be appointed the bishop of Trier in 1981. Spital, in fact, relayed to Böckenförde Keller's reservations in a four-page letter.Footnote ⁶⁶ Ideals of liberty and equality at the heart of the French Revolution, Keller asserted, had been ultimately made possible by the guillotine. For the sake of achieving a true democracy, it was the church's task to do away with ‘the rest of the guillotine’. Presumably this made the acceptance of a genuinely democratic state contingent on the willingness of a secular state to accept the demands of Catholics for their own protection against a hostile secularism.

Under his own name, Spital stepped forward in mid-January 1958 with a rebuttal in the Catholic weekly newspaper, Echo der Zeit.Footnote ⁶⁷ Their extended back-and-forth unveiled points of contention that echoed arguments just made in the recent battles over the Reichskonkordat and denominational schools.Footnote ⁶⁸ Spital's position was largely representative of the defensive posture endemic to Roman Catholicism in the early years of the Federal Republic.Footnote ⁶⁹ For Spital, democracy remained as fragile as the CDU's recent electoral gains: the other political parties would exercise a ‘tyranny of the majority’ once they had wrested political power from their ideological enemies through electoral gains.Footnote ⁷⁰ The CDU's ideological rivals could easily deny minorities like Roman Catholic fundamental political and moral rights like the ‘right of the parents’, as had indeed been the case during the Nazi and Kulturkampf eras. The fight, then, was for religious liberty.

Böckenförde, in contrast, no longer saw Roman Catholics as a beleaguered minority. Eight years of rule by a CDU chancellor was proof of change. But their disagreement was over more than whether the glass was half full or empty. Democracy, for Spital, was not an ethical norm. Nor could it be. The form of a state, Spital implied, was ethically neutral. For Böckenförde, by contrast, democracy necessarily assumed certain ethical norms – tolerance, openness and, above all, the willingness to grant others, even longstanding ideological foes from parties like the SPD, the opportunity to hold political power. And here, he made reference – and not for the last time – to Arndt's observation that democracy entailed agreement about ‘that which cannot be voted upon’ (das Unabstimmbare).Footnote ⁷¹

Böckenförde had sent an off-print of his article to Arndt on 24 November 1957. Arndt responded by sending the young scholar a printed copy of his talk from earlier in the year, ‘Christian Faith and Political Decision’ (Christlicher Glaube und politische Entscheidung), hoping that he might be able to secure a review in Hochland.Footnote ⁷² Every Catholic, Böckenförde wrote back, can agree with Arndt's practical conclusions. ‘If these principles are observed everywhere by your political friends’, and if from the church's side it is finally acknowledged that the Social Democrats are pursuing this path ‘not out of tactical advantage but from inner tolerance, then there is no longer any reason for the pastoral letters and election sermons that until now have been so common, Böckenförde opined.Footnote ⁷³ Yet Böckenförde also expressed reservations. Arndt had argued that a particular understanding of humanity undergirded liberal socialism, that man was not evil by nature, that each person had an ‘inviolable dignity’ (unantastbare Personwürde). With such an understanding, liberal socialism was open to all who shared its political goals, regardless of whether they arrived with a Christian, humanitarian or idealistic understanding of humanity. But precisely because of that, Böckenförde noted, there were certain domains in which Christian or Catholic understandings would lead one to accept or reject certain goals, such as the killing of the unborn. The Christian conscience, in certain instances, was the ultimate arbiter, even where Christians were called to anchor their conscience in God-given commandments and unchangeable cultural norms.Footnote ⁷⁴

For Böckenförde, the confirmation that Arndt and the SPD were acting out of principle and not out of tactics came only in 1959 and 1960. Arndt was an architect and author of the SPD's landmark Godesberger platform from 1959 famously renouncing Marxism.Footnote ⁷⁵ ‘Ultimate truths’ (letzte Wahrheiten), Arndt argued, had no place in party platforms: ‘Democratic socialism, which is rooted in Europe in Christian ethics, in humanism and in classic philosophy, does not seek to proclaim ultimate truth. It refuses to do so not out of the lack of understanding and not out of indifference towards Weltanschauungen or religious truths but out of respect for people's decisions, which should be determined neither by the state nor a political party.Footnote ⁷⁶

In an address Arndt delivered in 1960 to the Congress on Cultural Policy of the SPD in Wiesbaden, Arndt elaborated on these phrasings he had unveiled in the Godesberger Programme. If the political parties in a democracy differentiate themselves from each other not through their political opinions, which they recognise are bound to moments in history and therefore subject to change and error, but instead when one of the parties claims that its knowledge rests on a foundation of immutable and absolute truth, the parties stop being equal under the law.Footnote ⁷⁷ More importantly, Arndt reiterated his phrasing that the SPD no longer sought to proclaim eternal truths. The word ‘proclaim’, Arndt affirmed, is the central concept. The party does not wish to deny that eternal truths exist. Rather, the SPD seeks to leave it to individuals to act on these principles though their individual faith or reason (Denken).Footnote ⁷⁸

This talk captured Böckenförde's interest. If Arndt's principles could be realised, he wrote to Arndt in December 1960, there would no longer be cause for the steady stream of electoral sermons and pastoral letters from the bishops and for Catholics not to vote for the SPD, should they agree with its platform.Footnote ⁷⁹ Such a development, he added, would be of the greatest importance so that the ‘unfruitful ideological front lines so harmful to a democracy can finally disappear from the elections’. It depends, he wrote, on finding ways to ‘translate’ Arndt's ideas for a Catholic audience and finding ways to prevent the very powerful tactical and pragmatic interest in an alliance between the church and the CDU from continuing to establish itself as a matter of principle and conscience. If that were to take place, he concluded, much would be ‘won for our state as such’.

Böckenförde suggested convening a small circle to discuss these matters further, including their ‘practical side’. The circle, he wrote, could consist of the SPD politicians Herbert Wehner, Waldemar von Knöringen, Willi Eichler and Peter Nellen. His choice of these names was hardly coincidental: they reflected the transformation taking place at the highest ranks of the party. Nellen was a CDU politician representing Münster who had switched over to the SPD little more than one month earlier. Nellen's jump to the SPD on 8 November 1960 was for Böckenförde a ‘signal’, whose impact Böckenförde likened to that of a ‘mid-range earthquake’.Footnote ⁸⁰

Another architect of the Godesberger Programme, Herbert Wehner represented in many ways the power behind the SPD throne – and something of a political enigma.Footnote ⁸¹ A former communist, he retained the sharp rhetoric of the proletarian class warrior. While in exile in Moscow from 1937 through 1941, before leaving for Sweden, he appears to have provided information to the Soviet state that led to the denunciation and arrests of fellow German communists.Footnote ⁸² But he had a change of course, one possibly fashioned by his being excluded from the Communist Party on orders of the communist Politburo then headed by Wilhelm Pieck. Wehner returned to Germany in 1946 and immediately joined the SPD. He became determined to enable the SPD to be recognised as capable of governing legitimately and wisely (regierungsfähig) and to opening up the party ideologically. His semi-authoritarian personality and formidable presence appears to have been a greater asset than hindrance.

Like Wehner, Waldemar von Knöringen spent the Nazi years in exile, in his case, in Austria, Czechoslovakia, France and the United Kingdom, where he sought to organise the SPD resistance. As his name suggests, he was from the nobility, and he too was committed to opening up the party to those of different class backgrounds.Footnote ⁸³ To no surprise, this consummate outsider had been heavily involved in the drafting and promotion of the Godesberger Programme.

Arguably the most significant of these contacts and Godesberger Programme architects was Willi Eichler, a one-time rebel in the International Socialist Fighting League (Internationaler Sozialistischer Kampfbund; ISK) from 1926 until the end of the war.Footnote ⁸⁴ As with many of the youth involved in the ISK in the 1920s, Eichler had been almost rabid in his anticlericalism and even hostile to democratic currents. As late as 1936 the ISK programme declared the claims of all dogmatic teachings to be ‘presumptions of superstition’: this was an organisation of militant freethinkers dedicated not just to a separation of church and state but to stamping out the influence of the churches on the educational system.Footnote ⁸⁵ And yet it was Eichler who after the war helped take the lead in building bridges to organised religion, even waging an extensive written correspondence with the Catholic social theorist, Oswald Nell-Breuning, SJ.Footnote ⁸⁶ How does one explain this about-face? To be sure, the ISK did not reject all religious claims per se: it merely asserted that they were neither provable nor unprovable. In the absence of a militant atheism, according to one account, lay the foundation for a bridge between Catholicism and Socialism.Footnote ⁸⁷ But just as critical was the fact that Eichler like many others in SPD saw this rapprochement as an existential necessity. The need stemmed from the bitter lessons drawn from the collapse of the Weimar Republic and the pain of exile and resistance: socialists had to be able to cooperate with Catholics were future catastrophes to be avoided.

But Eichler had another reason for drawing closer to the churches, and it was one that Böckenförde shared, even if the latter did not emphasise it to the same degree. Eichler supported Christian notions of charity and their duty to the poor, the hungry and the stranger. And here Böckenförde agreed with the SPD agenda, which included a commitment to social welfare, principles of solidarity, social responsibility and balance (sozialer Ausgleich) and advocacy for those with less power or on the margins.Footnote ⁸⁸ But did not Catholic social teachings stress the same points? For Böckenförde, Catholic social teachings had gone into ‘hibernation’.Footnote ⁸⁹ They had been used to lend support to the social market economy but ultimately proved limited when it came to a reorganisation of capitalism and economic reform. In 1981 Böckenförde himself made this case before the Central Committee of German Catholics to commemorate the ninetieth anniversary of Rerum Novarum. The reaction to his talk was rather ‘restrained’.Footnote ⁹⁰ Nell-Breuning reported back to him that the higher-ups in the church heard his message emphasising the principle of (social) solidarity but were unwilling to take it up. They were too indebted, Böckenförde learned, to the principles of ordoliberalism exemplified in the writings of Cardinal Joseph Höffner, Keller's successor as the Bishop of Münster beginning in 1962 and the archbishop of Cologne from 1969 through 1987.Footnote ⁹¹

For Böckenförde, it was not the Catholic teachings that had come up short but rather their interpretation and implementation. This proved equally true for Catholic just war teachings. He and the Catholic philosopher Robert Spaemann, another member of the so-called ‘Ritter School’, had directly challenged the positions taken in 1960 and 1961 by Gustav Gundlach, SJ, who argued that use of atomic weaponry could be justified in certain instances. Both Böckenförde and Spaemann regarded Gundlach's claims a fundamental misreading – if not perversion – of Catholic just war doctrines.Footnote ⁹² In contrast, the SPD was waging a fight against atomic weaponry entitled ‘Fight Atomic Death’ (Kampf dem Atomtod). Spearheading protests across Germany, it began building bridges to religious groups and intellectuals self-identifying as Catholic or Protestant who for religious and moral reasons had taken the same position.Footnote ⁹³ Gustav Heinemann and Helene Wessel, two trenchant critics of Adenauer's atomic strategy, had both made headlines for joining the SPD in 1957. Heinemann was a devout Protestant, one who had been active in the Confessing Church; his wife had been a student of the renowned theologian, Rudolf Bultmann.Footnote ⁹⁴ It was with good reason that Böckenförde found himself drawn to the SPD's opposition to atomic weaponry.

These points of agreement notwithstanding, it took years – what he described as a ‘long process’ – before Böckenförde considered joining the SPD, his family background and spiritual formation hardly predetermining him to such a move.Footnote ⁹⁵ Böckenförde had met Arndt briefly in early 1958 after the SPD politician delivered a lecture at the student union in Munich. Seeing the twenty-seven-year-old student for the first time, Arndt expressed surprise. After reading his essay, Arndt had imagined the author to be an old, ‘bearded’ former Centre Party politician.Footnote ⁹⁶ Böckenförde remained in intermittent contact with the brilliant SPD jurist. After speaking with him by telephone in early 1963 Arndt helped set up an array of meetings for a fourteen-day tour of Bonn, including meetings with the SPD politicians, Erwin Schoettle, Hans Merten and Herbert Wehner. Böckenförde and one of his brothers met with Wehner at the latter's house in Bad Godesberg over the course of a Sunday afternoon.Footnote ⁹⁷ As Böckenförde mentioned that he was considering joining the SPD, Wehner listened eagerly but refrained from any efforts at persuasion, no doubt preferring to let Böckenförde's decision come from him alone.Footnote ⁹⁸ Following his fourteen days in Bonn, Böckenförde wrote to Arndt to inform him that everything had proceeded ‘to his fullest satisfaction’.Footnote ⁹⁹ Even so, Böckenförde did not yet join, preferring to remain a non-member who nonetheless had been invited to participate actively.Footnote ¹⁰⁰

Two years later and having just been given his professorship in Heidelberg, Böckenförde was invited to an SPD congress on its legal policy in Heidelberg in 1965 at which Arndt and former Bundespräsident Gustav Heinemann spoke. Böckenförde had the opportunity to meet with Arndt and other colleagues and hear Arndt vent his frustrations about his inability to have prevented new legislation extending the statute of limitations for war crimes during the Nazi era.Footnote ¹⁰¹ Even so, it was not until the formation of the Grand Coalition between the CDU and the SPD in 1966 that Böckenförde finally decided to join the party.

Once on board Böckenförde had a smooth ascent, one facilitated by the fact that his younger brother, Christoph, had begun serving the party as a floor leader (Fraktionsassistent) just fourteen days before the Grand Coalition took effect.Footnote ¹⁰² Ernst-Wolfgang Böckenförde served as a member of the Committee for Legal Policy advising the Party Executive (Rechtspolitischer Ausschuss beim Parteivorstand) from 1969 on as well as in the Study Commission for Constitutional Reform (Enquête-Kommission Verfassungsreform) after 1970. He delivered talks and lectures at political forums across Germany. Crucially, he served as an informal adviser to Chancellor Helmut Schmidt as well as a ghost writer on at least four separate occasions.Footnote ¹⁰³ The connection was introduced by the SPD's desk officer for the churches (Kirchenreferent), Burkhard Reichert, who set up a forty-five minute meeting between the two in 1976.Footnote ¹⁰⁴ Schmidt was preparing to take part in a discussion over ‘basic values’ (Grundwertedebatte), a debate that had broken out over questions of family and marriage law and over whether the state had the prerogative to advocate for questions of morals and values that had been the province of the church. Böckenförde opined that the state could not fulfil the ethical obligations that many would invest in it, a reiteration of his famous dictum from 1964 that asserted that the modern secularised state lives from presuppositions that it cannot guarantee.Footnote ¹⁰⁵ Schmidt insisted that Böckenförde write down this formulation, thus turning the constitutional theorist into a ghost writer for a speech that the chancellor delivered to the Catholic Academy in Hamburg on 23 May 1976. In an echo of Carl Schmitt, the state needed to function as a decision making unit (Entscheidungseinheit) in order to guarantee freedom as well as peace. But how could the state promote its own presuppositions, since the guarantee of individual freedoms is insufficient to hold a society together?Footnote ¹⁰⁶ For Böckenförde, a ‘certain we-feeling’ of mutual solidarity was necessary. But ultimately, the sole value of the state is the freedom not to prescribe values.Footnote ¹⁰⁷

Böckenförde also served as a ghost writer for Schmidt's path-breaking speech, ‘Peacemaking’, delivered to the Katholikentag in Düsseldorf on 3 September 1982.Footnote ¹⁰⁸ That a Protestant chancellor and SPD member could deliver a speech before the largest gathering of German Catholics on a topic so rife with controversy was itself a sign that Böckenförde's longstanding project to open up the politically insular world of Catholicism to onetime political rivals had succeeded.Footnote ¹⁰⁹ One year later – and sixteen years after he had joined the party – Böckenförde was appointed as a justice to the constitutional court on the recommendation of the SPD, the highest honour he could have received. Because of power sharing arrangements between the parties, a recently vacated slot on the court was to go to the SPD – and Böckenförde proved the logical choice for the party leadership.Footnote ¹¹⁰

What conclusions can be drawn from this story of ideological transformations? In serving as a Catholic bridge-builder to the SPD, Böckenförde helped bring about a rapprochement between the political elites at the top of the Catholic and socialist milieus. Bur like his fellow bridge-builders from both the SPD and the world of organised Catholicism, he was exceptional. As a rule, those reaching out to Catholicism from the SPD were not the prototypical representatives of the German socialist milieu who sought to uphold the rituals, values and traditions of the workers’ culture and organisations of the 1920s. More often than not, they were the outsiders – those from bourgeois or even upper-class backgrounds, or those who forced into exile in the 1930s and 1940s and had reflected on the reasons for the cataclysmic events from 1933 through 1945. Some, like Arndt, were devout Protestants, and nearly all had strongly recognised the points of compatibility between a tempered socialism and Christianity.

Even though they took place at rarefied levels, Böckenförde's efforts at bringing together the church and the heir of the socialist tradition in the German West were far more than symbolic. A man of unimpeachable integrity and the highest principles, Böckenförde gave greater legitimacy to a party long scorned by loyal Catholics. Böckenförde's decision to join the SPD was driven by sober, rational considerations emblematic of his own reflective and highly cerebral persona. It was not only consistent with but lay at the heart of his larger intellectual project – assuring a solid foundation for post-war German democracy by creating a democratic ‘substance’ and ‘ethos’ among the West German citizenry and its major political parties. Each party had to recognise its adversaries as equal citizens and competitors – and to grant them the same legitimacy they would give to their own supporters. Each party had to pledge unconditional support for a democratic order, even when it temporarily stood on the losing end. After all: how could a democracy sustain itself if its major parties, influential citizens and interest groups remained loyal to it only so long as they were capable of realising the planks of their ideological agendas? These were questions and convictions drawn out of a careful examination of the failure of Weimar, the wreckage of the Nazi past and the transition to a dictatorship in the communist East. For him and most of his fellow bridge-builders in the 1950s and 1960s, past and present were tightly intertwined.

Böckenförde's journey to the SPD was thus driven by both push and pull factors. He was pushed away from the CDU in the 1950s by his doubts about the church's genuine commitment to a democratic ethos. But these concerns could have been allayed by changes in the larger Catholic edifice following the Second Vatican Council. He found himself pulled to the SPD by its decision to abandon its Marxist heritage: it was no longer a party characterised by an unquestioning almost religious-like faith in its ideology (Weltanschauungspartei). Once in power from the late 1960s onward, the SPD even gained the ironic nickname as the ‘best CDU of all time’.Footnote ¹¹¹ Böckenförde could thus see Catholic social teachings being realised most fully by its rival, the SPD.

To a significant extent, this process of de-ideologisation also transpired within the CDU, its decision to enter into a Grand Coalition with the rival SPD underscoring this transformation. The Second Vatican Council with its affirmations of pluralism naturally made such a coalition more palatable, even to conservative Catholics. But the ground for this transformation was being laid already in the 1950s. Böckenförde's unease with the political affiliations of many of those most active in the ‘Catholic milieu’ stemmed from his annoyance at the often shameless electioneering by bishops like Michael Keller and its lack of compatibility with the democratic ethos necessary to sustain the fledgling republic. But in reality the links between the CDU and the church hierarchy were more tenuous than Böckenförde had imagined them to be.Footnote ¹¹² Adenauer had taken pains to reduce his dependency on the church hierarchy: the CDU was not the Centre Party of Weimar. And even some of the bishops like Archbishop Lorenz Jaeger of Paderborn had already in 1957 begun to show restraint in their political exhortations to the faithful.Footnote ¹¹³

This fact suggests another way to sum up this larger transformation, for which Böckenförde's entry into the SPD serves as a microcosm. For the Catholic Church and the SPD to come together, both sides had to relinquish part of their faith in their respective Weltanschauungen – or at least consider that there were legitimate alternatives to it, even those with which they fundamentally disagreed. By making ideologies a matter of reasoned discourse and rational choice instead of a matter of faith, the stage was set for the Catholic Church and trade unions to act as interest groups active in the political process as a matter of choice but not out of a ‘totalising’ conscience. In such a context, the once high walls between Catholicism and socialism could start to break down, first intellectually and then practically. Bridge-building thus led to the destruction of fortresses and walls, apt metaphors for Böckenförde's life-work of providing a more solid foundation for the democratic order.