Libertas, 13 - 16:

13. Moreover, the highest duty is to respect authority, and obediently to submit to just law; and by this the members of a community are effectually protected from the wrong-doing of evil men. Lawful power is from God, "and whosoever resisteth authority resisteth the ordinance of God";[6] wherefore, obedience is greatly ennobled when subjected to an authority which is the most just and supreme of all. But where the power to command is wanting, or where a law is enacted contrary to reason, or to the eternal law, or to some ordinance of God, obedience is unlawful, lest, while obeying man, we become disobedient to God. Thus, an effectual barrier being opposed to tyranny, the authority in the State will not have all its own way, but the interests and rights of all will be safeguarded -- the rights of individuals, of domestic society, and of all the members of the commonwealth; all being free to live according to law and right reason; and in this, as We have shown, true liberty really consists.

14. If when men discuss the question of liberty they were careful to grasp its true and legitimate meaning, such as reason and reasoning have just explained, they would never venture to affix such a calumny on the Church as to assert that she is the foe of individual and public liberty. But many there are who follow in the footsteps of Lucifer, and adopt as their own his rebellious cry, "I will not serve"; and consequently substitute for true liberty what is sheer and most foolish license. Such, for instance, are the men belonging to that widely spread and powerful organization, who, usurping the name of liberty, style themselves liberals.

15. What naturalists or rationalists aim at in philosophy, that the supporters of liberalism, carrying out the principles laid down by naturalism, are attempting in the domain of morality and politics. The fundamental doctrine of rationalism is the supremacy of the human reason, which, refusing due submission to the divine and eternal reason, proclaims its own independence, and constitutes itself the supreme principle and source and judge of truth. Hence, these followers of liberalism deny the existence of any divine authority to which obedience is due, and proclaim that every man is the law to himself; from which arises that ethical system which they style independent morality, and which, under the guise of liberty, exonerates man from any obedience to the commands of God, and substitutes a boundless license. The end of all this it is not difficult to foresee, especially when society is in question. For, when once man is firmly persuaded that he is subject to no one, it follows that the efficient cause of the unity of civil society is not to be sought in any principle external to man, or superior to him, but simply in the free will of individuals; that the authority in the State comes from the people only; and that, just as every man's individual reason is his only rule of life, so the collective reason of the community should be the supreme guide in the management of all public affairs. Hence the doctrine of the supremacy of the greater number, and that all right and all duty reside in the majority. But, from what has been said, it is clear that all this is in contradiction to reason. To refuse any bond of union between man and civil society, on the one hand, and God the Creator and consequently the supreme Law-giver, on the other, is plainly repugnant to the nature, not only of man, but of all created things; for, of necessity, all effects must in some proper way be connected with their cause; and it belongs to the perfection of every nature to contain itself within that sphere and grade which the order of nature has assigned to it, namely, that the lower should be subject and obedient to the higher.

16. Moreover, besides this, a doctrine of such character is most hurtful both to individuals and to the State. For, once ascribe to human reason the only authority to decide what is true and what is good, and the real distinction between good and evil is destroyed; honor and dishonor differ not in their nature, but in the opinion and judgment of each one; pleasure is the measure of what is lawful; and, given a code of morality which can have little or no power to restrain or quiet the unruly propensities of man, a way is naturally opened to universal corruption. With reference also to public affairs: authority is severed from the true and natural principle whence it derives all its efficacy for the common good; and the law determining what it is right to do and avoid doing is at the mercy of a majority. Now, this is simply a road leading straight to tyranny. The empire of God over man and civil society once repudiated, it follows that religion, as a public institution, can have no claim to exist, and that everything that belongs to religion will be treated with complete indifference. Furthermore, with ambitious designs on sovereignty, tumult and sedition will be common amongst the people; and when duty and conscience cease to appeal to them, there will be nothing to hold them back but force, which of itself alone is powerless to keep their covetousness in check. Of this we have almost daily evidence in the conflict with socialists and members of other seditious societies, who labor unceasingly to bring about revolution. It is for those, then, who are capable of forming a just estimate of things to decide whether such doctrines promote that true liberty which alone is worthy of man, or rather, pervert and destroy it.