O’Neill compares her writing to that of Kant in that she addresses the obligations experienced by one that allow another to define something as his right. This is very similar to the approach Kant took when writing the Metaphysics of Morals. This also differs considerably from the Rights Theory which considers rights, not obligations, as the basis of its arguments.
O’Neill’s argument begins with the idea that there are significant differences between the theories that claim that rights are fundamental and those that claim that obligations are fundamental. She then points out some of the ways in which an account of obligation based on the constructivist is more advantageous than an account of right. She further argued that when speaking in the context of issues regarding children, the approach that rights are fundamental contains some distinct political costs. Her conclusion, based on these arguments, seems to be that the appropriate approach to take with children in ethical issues would be that of obligations as fundamentals as rights as fundamentals proves to be neither theoretical nor political advantageous.
I think a fair argument would be that there is such a difference between rights and obligations that they are two separate arguments and not just opposite ends of the same argument. By this I mean that the question of someone’s rights is not contingent on another’s obligations. For example, my rights to free speech are affected by, but not based on, another’s obligations to listen to, or to consider, my expressed opinions. Simply because someone refuses to give my views appropriate consideration does not mean that I then lose my rights to express those views.