Last year, Christiane Tietz’s Karl Barth: A Life in Conflict was published in English for the first time. Although the true nature of Karl Barth’s relationship with his secretary, assistant, and “co-labourer” Charlotte von Kirschbaum has been public for some time, Tietz’s book gives English speakers more ready access to a thorough account.
Barth carried on a decades-long extramarital relationship with von Kirschbaum. Several years after the beginning of their relationship, Barth invited her to move in with his family, and she remained there for close to forty years. Barth’s wife Nelly was told of their feelings for one another from the beginning, and the decision to share a household between them was, on some level, acquiesced to by all parties. However, the arrangement was often extremely difficult for all three—perhaps especially the two women. The option of divorce was raised at certain points by each member of the party, but ultimately they chose to remain in an arrangement that they dubbed Notgemeinschaft: a term that Tietz translates as both “an emergency or necessary community” and “a community in distress.”
Although von Kirschbaum was well known for her invaluable assistance to Barth in his many years of writing the Church Dogmatics, the true nature of their relationship was not confirmed until 2000, when letters from both Barth and von Kirschbaum to their friend and confidante Eduard Thurneysen were published. In 2008, the full correspondence between Barth and von Kirschbaum was published. This is something that Barth’s children, also heirs to von Kirschbaum’s estate, had long intended. A statement from two of his children in 1993 expresses why they chose to release the letters for publication:
The letters have generated some academic engagement since their publication, although not as much as one what might expect, given the number of scholars engaged in Barthian studies. While Tietz’s book provides a clear historical account of the triangular relationship, presenting the different perspectives and experiences of all three players as accurately as possible, her work is a historical account, rather than a reflection on its theological import.
However, given that Barth is a theologian (arguably the most influential theologian of the twentieth century), the impact that this “unbearable” affair had on his theology—and the impact that the knowledge of his extramarital relationship has on us, his readers—must be explored. This is something that everyone studying or teaching Barth needs to engage seriously.
While I don’t have the expertise to consider specific ways that Barth might have adapted his theology to justify his actions, I do want to name a few “bad takes” that I have encountered, which I believe deserve a hearty “Nein!” in response:
1. “Barth was already having difficulties in his marriage when he met Charlotte.” It seems that Barth himself hinted at this. He wrote to Charlotte that “our marriage until now was for all the difficulties a happy story,” but added a few lines later, “I believe I understand, at least a little, how this [affair] became possible (I mean, from the perspective of our marriage).” While it could be true that Karl and Nelly had had difficulties, victim-blaming the spouse of someone who cheats on them is always a hard no.
2. “We are all sinners/every theologian sins/it’s not our place to judge.” This argument comes up whenever a theologian is found to be guilty of terrible things. While it is true that we are all sinners, and even that all theologians are sinners, this does not mean that we are not asked to make right judgments about someone’s actions or the ways that these actions are implicated in their theologizing.
3. “Without Charlotte von Kirschbaum’s presence in Barth’s life, the Church Dogmatics as we know it could not have been written.” This statement is very true. Barth himself acknowledged that von Kirschbaum was indispensable to his work. However, when this fact is used as justification of Barth’s adulterous relationship with von Kirschbaum, the underlying statement being made is that the “theological good” of the Church Dogmatics, or of Barth’s contribution to theology more generally, was worth the harm suffered by the women in his life.
We can see this logic applied by Barth’s own children in their statement quoted above. von Kirschbaum’s assistance was so necessary to Barth’s work that his children even understood their mother’s acceptance of von Kirschbaum’s presence in their household as “her significant part of the work.”
Theologian George Hunsinger seems to appeal to this same logic, when he writes that Barth “could not have been what he was, or have done what he did, without [von Kirschbaum].”
It is true that Barth could not have been what he was or done what he did without von Kirschbaum, and it is important to acknowledge her vital contribution to his work. However, when discussing and reflecting on the Barth-von Kirschbaum relationship—a vital practice for anyone reading or teaching Barth—we need to steadfastly refuse a logic that sees the harm of Barth’s relationship with von Kirschbaum on all parties involved as reasonable collateral damage for the “good” of the Church Dogmatics. The production of a brilliant piece of theology is never sufficient justification for harming others.
 Christiane Tietz, Karl Barth: A Life in Conflict (Oxford: Oxford University Press, 2021). In her discussion of von Kirschbaum, Tietz draws extensively from her earlier article “Karl Barth and Charlotte von Kirschbaum” (Theology Today 74:2 : 86-111).
 Sarah Shin, “The Challenge of Biography: Reading Theologians in Light of their Breached Sexual Ethics,” Studies in Christian Ethics, original research article Nov 2021, DOI: 10.1177/09539468211059485, 17.
 Eberhard Busch’s biographical chapter covering 1921-1935 in The Oxford Handbook of Karl Barth (ed. Paul Dafydd Jones and Paul T. Nimmo [Oxford: Oxford University Press, 2019]) has only one brief paragraph about Barth’s relationship with von Kirschbaum. He writes rather misleadingly that Barth and von Kirschbaum would have married “if Nelly had consented to a divorce” (39). In fact, Nelly agreed to a divorce in May 1933, but Barth and von Kirschbaum decided against it, ostensibly because they felt a divorce was not her true wish (Tietz, 217).
 Tietz, 197 (footnote 105).
 Franziska and Markus Barth, “Entwurf zu einem Vorwort für die Ausgabe der Briefe zwischen Karl Barth und Charlotte von Kirschbaum,” cited in Briefwechsel Barth–von Kirschbaum I (GA 45), xix. As quoted in Tietz, 177-178.
 Sarah Shin’s excellent article offers a helpful model for approaching Barth in light of the affair with Kirschbaum. It is available open access at the DOI given above.
 Quoted in Tietz, 181.
 Tietz, 220.
 Hunsinger also describes von Kirschbaum (accurately) as “gripped by a sense of the greatness of Barth’s contribution.” Review of Suzanne Selinger’s Charlotte von Kirschbaum and Karl Barth: A Study in Biography and the History of Theology (1998), Princeton Theological Seminary Center for Barth Studies website: https://barth.ptsem.edu/charlotte-von-kirschbaum-and-karl-barth/