One would have thought that a restrictive interpretation of the decree of Vatican II on the lay apostolate would favour the movements of Catholic Action from an institutional point of view. And yet it is these movements that seem to be the most affected by a series of crises caused by their political or ideological orientation. They experience considerable disaffection. On the other hand, the 1970s have witnessed signs of a spiritual renewal outside the established structures. Although this renewal sometimes appears more qualitative than quantitative, the succes of the recent Journées Mondiales de la Jeunesse has shown its indeniable vitality.