56 We must add, therefore, that it is in the nature of the common good that every single citizen has the right to share in it—although in different ways, depending on his tasks, merits and circumstances. Hence every civil authority must strive to promote the common good in the interest of all, without favoring any individual citizen or category of citizen. As Pope Leo XIII insisted: "The civil power must not be subservient to the advantage of any one individual, or of some few persons; inasmuch as it was established for the common good of all." (40) Nevertheless, considerations of justice and equity can at times demand that those in power pay more attention to the weaker members of society, since these are at a disadvantage when it comes to defending their own rights and asserting their legitimate interests. (41)
Source: Pacem in Terris (Vatican.va)