The period that followed the promulgation of "Presbyterorum ordinis" was marked by a severe drop in the number of priestly vocations in the Western World. Church leaders argued age-old secularization was to blame and that it was not directly related to the documents of the council. Historians also pointed to the damage caused in 1968, by the sexual revolution, and the strong backlash over "Humanae vitae". Yet, other authors asserted the drop in vocations was at least partly deliberate as part of an attempt to de-clericalize the Church and allow for a more pluralistic clergy. In 1995, according to the Congregation for the Clergy, in recent years, "despite various persistent difficulties, there is a positive quantitative and qualitative recovery which makes one hope for a priestly second spring."