In a stable and civilized society when a man and woman conceive a child together they have a moral contract, whether state sanctioned or not, obligating them to mutually raise that child to adulthood. That contract requires them, in the absence of death or disability, to love, nurture, educate, clothe, and house their children together; in other words, shared parenting.
It is implied that carrying a child to term today is a voluntary act and that acts of passion do not lift the moral burden of parenthood. And neither the mother or father can shed that moral burden if society is to endure. Nor can a court or other state agency sunder that contract in the absence of disability or moral turpitude proven beyond a reasonable doubt before a jury of their peers.
However, it is quite plain that people change as they age, and nowhere is that more evident than with children. Clearly babies need their mothers as males don't lactate. But as children become teenagers, while both parents are still needed, experience shows they usually grow into mature adults best if their biological father is present and active in their lives.
Ideally, as the passion of the parents fades with age, they grow into best friends and share the joy of parenting their children together. However, life is ofttimes not ideal and the parents grow apart. That in no way alleviates the burden of the moral contract they assumed when they became parents. But forcing the parents to live together may make the situation worse. Be that as it may, there is no reason the mother and father cannot live in close proximity to one another until the children are grown so the little people can go freely back and forth between mom and dad at their pleasure and whim.
In my experience such arrangements have taken many forms. In some cases the parents simply live in different parts of the same house, ofttimes due to economic circumstances. At other times parents have what I refer to as a "duplex marriage." Mom and dad have separate residences in the same apartment building, condo complex, or even homes in the same neighborhood, with the parents sharing responsibilities as life's fortunes dictate. But human relationships have virtually infinite dimensions and cannot be specified in law or court. The critical factor for shared parenting is, regardless of the parents arrangements or relationships, that they live in close enough proximity that their children can easily walk the distance between them.
Clearly the role of the State in such arrangements is minimal or non-existent. One might suggest the law and courts might require the parents live within a specified maximum distance of each other while the children are growing up. It is very difficult for a parent to fulfill their moral contract if the other parent has absconded with the children to another state or country.
Where the parents are economically stressed, suffering from sickness or disease, or otherwise troubled, the role of social agencies must be limited to providing assistance to the parents. As noted above, only where moral turpitude has been unquestionably proven may the state justifiably terminate parental rights. Even then the children must go to their nearest relatives rather than strangers whenever possible.
Above all it must be remembered that children are to be shared and loved, not made pawns of by vindictive parents or controlled by the State. On this Christmas Day I can only imagine the terror and fear suffered by children whom the State has forcibly taken from their parents and cast into foster homes run by all-too-often uncaring strangers. And the heartbreak of fathers and mothers who have lost their children on this day-of-days when all the family should be gathered round sharing the blessings of this Christmas Day is gut-wrenching to contemplate.