The theory of parental responsibility is a simple idea with profound implications. Parents are causally responsible for placing their children in a state of peril, as a result of having created them. This is why parents have enforceable positive obligations to their children. The obligations are to remove the peril by raising the children to the self-sufficiency of adulthood. One of the mind-blowing implications of this idea is that parents cannot legitimately give up or pass on their obligations.
Imagine the following scenario: I am your neighbour and I have decided to make a huge bonfire in my garden. The fire begins to burn out of control, at risk of spreading and setting fire to your house. I call the fire brigade, who arrive before the flames have reached your house. I decide I am not enjoying this stressful situation, so I leave the firefighters to their work and walk off. Despite their efforts, the firefighters fail to contain the blaze and you return home to find that your house has been burned down.
When you confront me about what I have done, I make the following argument in my defence:
Yes, I may have started the fire that created the risk to your house, but I called the fire brigade to deal with it, so I passed on the problem to them. When I left, your house was untouched. If the fire brigade didn't stop the fire from reaching it, it is their fault. As soon as I passed the problem on to them, I wasn't involved anymore. If you have a problem, you should take it up with them.
Clearly this is not a legitimate argument. You would be right to object that I am the one who caused the problem in the first place. Regardless of whether I sought help to address the problem, I am still ultimately responsible for creating the risk to your property. Even if some kind of negligence on the part of the firefighters contributed to their failure to stop the blaze, that might imply some additional liability for them, but that surely would not get me off the hook for my role in creating this mess.
Here is another scenario: I push you into a lake and you cannot swim. I am also unable to swim, so I could not rescue you myself even if I wanted to. However, my inability to swim does not mean that I am free of any responsibility to you for your predicament. As the one who pushed you into the lake, I am obliged to get you the help that you need, otherwise I will be responsible for homicide. I must find help, such as a lifeguard or some volunteer willing to jump in to save you. And if the lifeguard or volunteer tries and fails, I am still responsible for your peril. I don't get to just walk off. I'm not off the hook for the problem I caused just because I asked someone else to try to sort out the problem for me. It is still my fault that you are drowning.
The important point about these scenarios is that I do not lose my obligation to you, even though I delegated actions to someone else. Although I can legitimately engage an agent to act on my behalf, I am still ultimately responsible for the obligation. Regardless of any agreements I make with my agent about what they will do for me, that doesn't change the obligation that I still hold to you because you never agreed to release me from my obligations. The same logic applies to parental obligations towards children.
Unintended Parenthood
Applying the principle to cases of unintended parenthood shows that parental obligations cannot be simply given up. The principle is that obligations can be incurred for the consequences of one's actions if those consequences were reasonably foreseeable, regardless of whether the consequences were intended or not.
Even if I did not intend to let my bonfire get out of control and burn down your house, I'm still responsible if that happens. Furthermore, even if I did my very best to stop the fire once it got out of control, I'm still the one who created the risk of an enormous bonfire in the first place. I'm still responsible.
The same logic applies to parents who did not intend to have a child. Parents cannot absolve themselves of obligations on the basis that they never wanted to have kids, nor on the basis that they actively tried to prevent this outcome by using contraceptives. If you take actions that could result in the existence of a child (i.e have consensual sex) then you are responsible for the child, even if you didn't intend it or want it. As Nathaniel Branden put it;
The fact that the parents might not have desired the child, in a given case, is irrelevant in this context; he is nevertheless the consequence of their chosen actions–a consequence that, as a possibility, was foreseeable.
Even if one parent is willing to raise the child alone, the willing parent cannot legitimately offer to be a single parent and to relieve the reluctant parent of all obligation. This cannot be done since the obligation is to the child, not the other parent. Parents are jointly and severally liable to their children. The children have legitimate claims against both parents to fulfil parental obligations. In fact, what the willing parent in this scenario would effectively be "offering" is to collude in denying the child his legitimate claims on one of his parents. Regardless of whether or not the unwilling parent accepted such an offer, it would not relieve his or her enforceable obligations to the child.
Parents Who Give Up Their Child For Adoption
Parents cannot absolve themselves of their obligation solely by passing on responsibility to an adopter, because a parent's obligation is to the child. Since a child cannot contract, the child cannot be said to have agreed to give up his claim on his parents. Therefore, parents who give their child up for adoption cannot rely on this act removing their obligation under the objective rule of creation of peril.
If I push you into a lake, my inability to swim does not mean that I am absolved of my responsibility to save you from drowning. I must find someone to rescue you on my behalf. Similarly, if parents cannot raise a child, they must find someone else to do so. But this does not absolve them of obligation for the child's peril.
If parents give their child up for adoption, this act should rightly be construed as delegating the responsibility to the adopters to fulfil the obligation on their behalf. The biological parents still remain the ultimate obligation holders. Therefore, if the adoptive parents were to mistreat the child, the biological parents could share liability for this crime since they still have enforceable positive obligations to the child.
As I have argued elsewhere, a victim of rape does not have parental obligations and so may legitimately give up a resultant child for adoption. However, no parents who have obligations can legitimately lose those obligations with adoption.
Although a biological parent cannot absolve themselves of parental responsibility by giving up a child for adoption, there are some circumstances when they can legitimately pursue adoption as a form of delegating responsibility. If the parents are objectively unable to look after a child (for example, owing to debilitating or terminal illness) then it would be a legitimate act of fulfilling parental obligations to delegate responsibility to an adopter. If for some reason the parents are demonstrably incompetent to look after themselves, let alone a child, then it would be legitimate to delegate responsibility to adopters.
Even in such cases, the biological parents do not absolve themselves of enforceable obligation. Calling on adoptors is like calling the fire brigade to put out my bonfire or calling a lifeguard to save someone I pushed into a lake. The actions of such rescuers do not absolve the person who caused the peril from their ultimate responsibility.
Given that a child can never be said to consent to adoption, the biological parent has never really lost their obligation, but rather they have effectively instructed an agent to fulfil the obligation on their behalf. If the adoptive parent failed to fulfil obligations on behalf of the parent, the child would arguably still have an enforceable claim against the original parent for having failed to fulfil their obligations.
Whether it is legitimate or not, some parents do in fact give up children for adoption, and it may well be in the best interests of the children for everyone to support this process even in cases where the delegation is not justified. Supporting adoption does not change the fact that the biological parents are failing to fulfil their valid obligations, but adoption may just be the best way to address a bad situation and ensure that a vulnerable child receives care.
Many have argued that is best to recognise the institution of bankruptcy, even though they also think that it is wrong to default on debts that have been voluntarily incurred. In a similar way, I do not think that the practice of adoption should be banned even in those cases where it is a clear dereliction of parental duty, but that does not imply that it is legitimate for parents to fail to fulfil their obligations.
Even if adoption is in the best interest of the child, it is also in the best interest of the child for the unfulfilled obligations of the biological parents to remain actionable in case the child needs them. This could involve financial support, forced heirship, or other ways in which a biological parent's obligations could be enforced.
Gamete Donors/Sellers
Since parents cannot legitimately pass on their obligations, the practice of gamete donation/sale must be illegitimate. Gamete donation/sale involves an unjust abdication of parental obligation by the gamete owner.
As has been argued by James Lindemann Nelson and Rivka Weinberg, making one's gametes available is the crucial act necessary to create a child. Therefore, those who make their gametes available are the parents of any resultant child. In most cases the parents are simply those who made their gametes available through having sex. In the case of gamete donation or sale, the sperm or egg donors/sellers are parents. They may have used other means than sex, but they are nonetheless the ones who made their gametes available.
This means that gamete donors/sellers are parents who are not fulfilling their obligations to their children. It would be wrong for me, as your neighbour, to start a huge bonfire in my garden that I know will endanger your house, and then walk off knowing that I have created a risk to you. Similarly, it is wrong to take actions that you know will create a child who is in peril and then remove yourself from any responsibility for the peril that the child faces.
This is the most wantonly irresponsible kind of parenting, since the parents deliberately cause the creation of children whilst never having any intention of fulfilling their obligations. They do not even have any involvement in ensuring that the adopters are able to fulfil obligations on their behalf. They take no care of the children that they cause to be created.
Conclusion
Even if a different set of people are arguably better candidates to raise a child (by having more resources, a more stable home etc), this does not legitimate a transfer of obligation by biological parents. As James Lindemann Nelson has argued:
It is not so much a question of knowing that the biological parents can do a better job than possible replacements; it is more a matter of continually being at hand to answer for one's own responsibilities. With respect to anyone else, the best I can do is predict that they will fufill their duties, but my relationship to my own agency is categorically different; I can bring myself—at least sometimes—to perform my duties.
Parental obligations are only fulfilled once a child reaches the safety and self-sufficiency of adulthood. At this point, the peril that the child faced as a result of being created has been overcome. Once the child has become an independent person capable of taking responsibility for his own actions, the parents are no longer obliged to remove the peril associated with childhood as the peril has dissipated. But until they are grown up, you have enforceable obligations to any and all children that you create.