Between protestant silence and catholic inflation, the «Groupe des Dombes» has opened a way of convergence in the field of mariology. Protestants are invited to take a new look at the «cooperation of Mary». Considered as an expression of the justification by grace and through faith, which is the prime principle of the Reformation, this doctrine allows us to tackle the marian dogmas without having to subscribe to them in a univocal sense or in a sense that would contradict the Gospel message. If the invocation of Mary and the saints remains an insuperable difficulty for a protestant, the universal intercession, as an integral part of the divine praise, unites the militant Church and the triumphant Church. Taking into consideration the principle of the «hierarchy of truths» which here operates, we see that the legitimate differences which remain are no longer a cause of division.