Justice requires that to lawfully constituted Authority there be given that respect and obedience which is its due; that the laws which are made shall be in wise conformity with the common good; and that, as a matter of conscience all men shall render obedience to these laws.
Pope Pius XIHowever we may pity the mother whose health and even life is imperiled by the performance of her natural duty, there yet remains no sufficient reason for condoning the direct murder of the innocent.
Pope Pius XIEducation belongs pre-eminently to the church ... neutral or lay schools from which religion is excluded are contrary to the fundamental principles of education.
Pope Pius XIThose wretches tainted with the error of Indifferentism and Modernism hold that dogmatic truth is not absolute, but relative: that is, that it must adapt itself to the varying necessities of the times and the varying dispositions of souls, since it is not contained in an unchangeable revelation, but is, by its very nature, meant to accommodate itself to the life of man.
Pope Pius XIWhether considered as a doctrine, or as an historical fact, or as a movemement, socialism, if it really remains socialism, cannotbe brought into harmony with the dogmas of the Catholic church.... Religious socialism, Christian socialism, are expressions implying a contradiction in terms.
Pope Pius XI