123 But not only in regard to temporal goods, Venerable Brethren, is it the concern of the public authority to make proper provision for matrimony and the family, but also in other things which concern the good of souls. just laws must be made for the protection of chastity, for reciprocal conjugal aid, and for similar purposes, and these must be faithfully enforced, because, as history testifies, the prosperity of the State and the temporal happiness of its citizens cannot remain safe and sound where the foundation on which they are established, which is the moral order, is weakened and where the very fountainhead from which the State draws its life, namely, wedlock and the family, is obstructed by the vices of its citizens.
Source: Casti Connubii (Vatican.va)