In this article, Macklin argues that future generations cannot properly be said to have rights, but that we ought to still give them moral consideration when acting in the present.
Her main argument is fairly simple, she says that future generations cannot have rights because they do not exist to be subjects of rights. She asks us to compare how we treat duties and rights, stating that these ought to be treated the same way unless we have a good reason to do otherwise. Typically we do not say that non-existent people have duties (I put this too weakly, I have never heard people say this). If a non-existent person cannot have duties then, since duties and rights almost always travel in a single package, non-existent people cannot have rights either.
But, says the critic, we commonly give people or other things rights without giving them duties. Macklin lists the mentally disabled, the young, the sick, and the old, but I would also like to add non-human animals to this list (although all of these are still under dispute, let’s assume that they do in fact have rights). However, according to Macklin these groups have rights solely in virtue of the fact that they are sentient. And, as it turns out, sentience is sufficient for rights, but it is also a necessary condition. So, concedes Macklin, there is a slight asymmetry between rights and duties, but nothing to be worried about as these two still go together in the case at hand.
Assuming that her argument was successful, she concludes that future people cannot have strict rights, but might still be subject to our moral consideration. She says that under a utilitarian type calculus the overall balance of pleasure over pain would take future people into account, so we can give future people some consideration without giving them the strong protection of absolute rights.
The first point of criticism is that the utilitarian calculus might be subject to the same problem as the one she identified for rights (Parfit calls this the non-identity problem). As she said in a footnote, she wants to work within the same framework that Parfit described, so she is certainly aware of the non-identity problem. The problem is that when we speak of maximizing the good, while there aren’t any explicit constraints on how far we can calculate into the future, it seems to me that the calculus could conceivably be restricted to existent sentient beings. I’m not confident on this criticism, and I don’t know what modern scholarship on the non-identity problem says, so I leave this as an open criticism for the moment.
The second point of criticism is against her approach in distinguishing between rights and lesser (utilitarian) morality. In addition to the problem I described above, we might wonder what rights are supposed to do in the context of justice and human rights in general. For instance, we might reject all rights as just a veiled way of saying that ‘such and such judgments of morality are so central to our thought that we give them the name rights’. If that is the case then we might be able to expand ‘rights’ to anything we find central to morality. In other words, describing rights as ontological entities that only living beings can have is a rather limited view of rights.