Pacem in Terris §16

¹⁶ The family, founded upon marriage freely contracted, one and indissoluble, must be regarded as the natural, primary cell of human society. The interests of the family, therefore, must be taken very specially into consideration in social and economic affairs, as well as in the spheres of faith and morals. For all of these have to do with strengthening the family and assisting it in the fulfilment of its mission.