13 Hence, mindful of Our Apostolic charge and conscious of the imperious duty incumbent upon Us of defending and preserving against all assaults the full and absolute integrity of the sacred and inviolable rights of the Church, We do, by virtue of the supreme authority which God has confided to Us, and on the grounds above set forth, reprove and condemn the law voted in France for the separation of Church and State, as deeply unjust to God whom it denies, and as laying down the principle that the Republic recognizes no cult. We reprove and condemn it as violating the natural law, the law of nations, and fidelity to treaties; as contrary to the Divine constitution of the Church, to her essential rights and to her liberty; as destroying justice and trampling underfoot the rights of property which the Church has acquired by many titles and, in addition, by virtue of the Concordat. We reprove and condemn it as gravely offensive to the dignity of this Apostolic See, to Our own person, to the Episcopacy, and to the clergy and all the Catholics of France. Therefore, We protest solemnly and with all Our strength against the introduction, the voting and the promulgation of this law, declaring that it can never be alleged against the imprescriptible rights of the Church.
Source: Vehementer Nos (Vatican.va)