14 We deem those associations peculiarly fitted to aid them in this work which are, so to speak, the auxiliary forces destined to support the interests of the Catholic religion; and We approve, therefore, their object and the energy they display; We ardently desire that they may increase in number and in zeal, and that from day to day their fruits may be more abundant. But since the object of such societies is the defence and encouragement of Catholic interests, and as it is the Bishops who, each in their proper diocese, have to watch over those interests, it naturally follows that they should be controlled by their Bishops, and should set great value on their authority and commands. In the next place they should with equal care apply themselves to preserving union, first because on the agreement of men's wills all the power and influence of any human society depends; and next, because in the societies of which We speak that mutual charity should especially be found which necessarily accompanies good works and is the characteristic trait of those whom Christian discipline has moulded. Now as it may easily happen that the members may differ on politics, they should recall to themselves the aim of all Catholic associations, and thereby prevent political partisanship from disturbing their cordial unity. In their discussions the members ought to be so completely penetrated by the thought of the purpose they united for as to seem of no party, remembering the words of the Apostle St. Paul: "For as many of you as have been baptized in Christ have put on Christ. There is neither Jew nor Greek; there is neither bond nor free.... For you are all one in Christ Jesus"(6). Such rules of conduct will lead not only to amiable and friendly relations among the several members of these societies, but also between societies of a similar character, an object extremely desirable. Thus, by the exclusion of party rivalries, the principal sources of dispute will be avoided; and all will be enlisted in the service of the one cause, the highest and noblest, about which no disagreement can exist among Catholics worthy of the name.
Source: Cum Multa (Vatican.va)