Karl Rahner was a German Jesuit priest and theologian who, alongside Henri de Lubac, Hans Urs von Balthasar, and Yves Congar, is considered to be one of the most influential Catholic theologians of the 20th century. He was the brother of Hugo Rahner, also a Jesuit scholar.

Hans Urs von Balthasar was a Swiss theologian and Catholic priest who is considered one of the most important Catholic theologians of the 20th century. With Joseph Ratzinger and Henri de Lubac, he founded the theological journal Communio. Over the course of his life, he authored 85 books, over 500 articles and essays, and almost 100 translations. He is known for his 15-volume trilogy on beauty, goodness (Theo-Drama), and truth (Theo-Logic).