Karl Marx | Karl Pilkington | Karl Lagerfeld | Karl G. Heider | Karl Rove | Karl Pearson | Karl May | Karl Liebknecht | Karl Friedrich Schinkel | Karl Dönitz | Karl Jenkins | Karl Stefanovic | Karl Bodmer | Karl Wilhelm Friedrich Schlegel | Karl Malone | Karl Wolf | Karl Valentin | Karl Popper | Karl Malden | Karl Kesel | Karl Barth | Karl Richard Lepsius | Karl Philipp von Wrede | Karl Kautsky | Karl Johans gate | Karl-Heinz Kämmerling | Karl | Karl Weierstrass | Karl Story | Karl Scheel |
It was originally formed after complaints by some of the more traditionalist bishops of the presence of Protestants and liberal Catholic theologians such as Hans Küng, Joseph Ratzinger (the future Pope Benedict XVI) and Karl Rahner.
Already in 1963, together with Chenu, Congar, Karl Rahner, and Hans Küng he was involved in preparing the rise of the new theological journal Concilium, which was officially founded in 1965 with the support of Paul Brand and Antoine Van den Boogaard, and which promoted "reformist" thought.
Optatam Totius influenced German Roman Catholic theologian Karl Rahner to write his work The Founndation of Christian Faith.
After ordination, he spent a semester in Münster, Westphalia, studying under the theologian Karl Rahner, before he transferred to the University of Regensburg to do his doctoral studies under the supervision of the then Professor Joseph Ratzinger.
He became influenced by the Catholic theologian Karl Rahner, thinker Pierre Teilhard de Chardin, and Christian mystics, who became the object of his theological reflection.