The book is entitled, Gratwanderung: Briefe der Freundschaft an Karl Rahner. That translates into Balancing act: Letters of friendship to Karl Rahner.
Here are some of the contents of the book: It is an image out of sync with the persona of a German academic: Jesuit Fr. Karl Rahner on his knees before a woman, overwhelmed with gratitude for his love, for a passionate relationship with a 51-year-old widow and two-time divorcee that would produce some 4,000 letters between 1962 and Rahner's death in 1984. Rahner, considered by many to be the 20th century's most creative Catholic theologian, was 58 when German novelist Luise Rinser played the image back to him in a letter dated Aug. 10, 1962. "My Fish, truly beloved, I cannot express how shaken I was as you knelt before me," she wrote.
"You were kneeling before the Love that you are experiencing and before which I also kneel in amazement, in reverence, with trembling and with an exultation that I hardly dare to allow myself to feel. We are both touched in the innermost part of our being by something that is much stronger than we anticipated."
The passage is from letters that Rinser wrote to Rahner over the 22 years of their relationship. Published in German, the letters hold a particular fascination for Pamela Kirk, a theologian who teaches at St. John's University in Jamaica, N.Y. While there has been virtually no public discussion of the letters in the United States, she has delivered two papers on the Rinser-Rahner relationship at the Catholic Theological Society of America.
Link (here) to read the extensive article first published in the National Catholic Reporter