17 In such organization of the State there is nothing that can be thought to infringe upon the dignity of rulers, and nothing unbecoming them; nay, so far from degrading the sovereign power in its due rights, it adds to it permanence and luster. Indeed, when more fully pondered, this mutual co-ordination has a perfection in which all other forms of government are lacking, and from which excellent results would flow, were the several component parts to keep their place and duly discharge the office and work appointed respectively for each. And, doubtless, in the constitution of the State such as We have described, divine and human things are equitably shared; the rights of citizens assured to them, and fenced round by divine, by natural, and by human law; the duties incumbent on each one being wisely marked out, and their fulfilment fittingly insured. In their uncertain and toilsome journey to the everlasting city all see that they have safe guides and helpers on their way, and are conscious that others have charge to protect their persons alike and their possessions, and to obtain or preserve for them everything essential for their present life. Furthermore, domestic society acquires that firmness and solidity so needful to it from the holiness of marriage, one and indissoluble, wherein the rights and duties of husband and wife are controlled with wise justice and equity; due honour is assured to the woman; the authority of the husband is conformed to the pattern afforded by the authority of God; the power of the father is tempered by a due regard for the dignity of the mother and her offspring; and the best possible provision is made for the guardianship, welfare, and education of the children.
Source: Immortale Dei (Vatican.va)