“Multi-culti” – a catchword we all know. A concept that today is looked at rather critically but, in past decades, was to a large extent a guideline for the shared life of Christians and Muslims in Europe, even if by far not everyone was aware of this premise. Multi-culti – a result of an historical development into which we have stumbled rather than consciously planned and controlled. A development that, in addition, resulted from the false intellectual premises that accompanied the contemplation of the migration of Muslim workers to Germany, as well as from indifference and ignorance.