All Catholics must make themselves felt as active elements in daily political life in the countries where they live. They must penetrate, wherever possible, in the administration of civil affairs; must constantly exert the utmost vigilance and energy to prevent the usages of liberty from going beyond the limits fixed by God's law. All Catholics should do all in their power to cause the constitutions of states and legislation to be modeled on the principles of the true Church.
Pope Leo XIIIWe have seen that this great labor question cannot be solved save by assuming as a principle that private ownership must be held sacred and inviolable. The law, therefore, should favor ownership, and its policy should be to induce as many as possible of the people to become owners.
Pope Leo XIIIThe first law of history is to dread uttering a falsehood; the next is not to fear stating the truth; lastly, the historian's writings should be open to no suspicion of partiality or animosity.
Pope Leo XIII