8 The new Spanish legislators, indifferent to these lessons of history, wanted a form of separation hostile to the Faith professed by the great majority of citizens, - a separation so much more painful and unjust especially since it was advanced in the name of that liberty promised and assured to all without distinction. Thus they wished to subject the Church and her ministers to measures by which they sought to put her at the mercy of the civil power. Infact, while under the Constitution and successive laws all opinions, even the most erroneous, have wide fields in which to manifest themselves, the Catholic Religion alone, that of almost all of the citizens, see its teaching odiously watched, its schools and other institutions, so helpful for science and Spanish culture, restrained.
Source: Dilectissima Nobis (Vatican.va)