Q&A 1, First Answer

My question is: Does Cohen’s argument lead to the conclusion that humans who are not fully sentient adults (for example, young children) are no more valuable than trees?

I think so.  If one absolutely must be a moral agent in order to have rights, then neither trees nor young children have rights.  This conclusion is obviously troubling.  I do not know if Cohen has responded at length to this criticism, but I can hypothesize a few ways he might do so if he chose.

First, he might argue that children have value because they are potential moral agents.  The argument from potentiality (more commonly seen in debates on abortion), however, is rife with problems.  We cannot know the future, so there is a definite chance that a child will never mature into a moral agent.  There is also the possibility that the child will grow into a moral agent who harms many other moral agents, to the point that it would be better if they had never achieved agency.  The argument from potentiality is also incompatible with the idea of indirect value, since any thing has the potential to become something a moral agent values; if we accept both arguments, we cannot harm anything in any case, which seems ridiculous.  Additionally, potentiality only applies to those children with the potential to become moral agents, meaning that abusing a terminally ill child, a mentally disabled child, or a mentally disabled adult for that matter, is perfectly ethical.  Lastly, to borrow from the debate on abortion, we must ask at what point something becomes a potential agent.  If a child is a potential moral agent and therefore valuable, does a fetus have the same status, making abortion wrong on the grounds of potential agency?  Is a zygote a potential moral agent?  Are the as-yet-uncombined sex chromosomes contained inside sexually mature humans potential moral agents, making the use of birth control unethical, and in fact making it morally wrong to do anything but attempt to reproduce as often as possible?  This also seems ridiculous, forcing us to conclude that the value of children stems from something other than potentiality.

Second, Cohen could argue that the value of children stems from the sentimental value moral agents place on them.  Children tend to engender very strong sentimental attachments from adult humans, giving them quite a lot of value in that way.  Yet this argument, too, has flaws.  If children obtain value only through the attachment of moral agents, it is not unethical to harm or kill a child for whom no one cares - a street child, perhaps - provided that you ensure no moral agents are harmed by, say, discovering the child's body later on.