Kant thought that moral agency, or rational moral agency, was the sole basis for moral status. He wrote "Two things find the mind with ever new and increasing admiration and awe, the oftener and more steadily we reflect upon them: the starry heavens above me and the moral law within me" [I. Kant. Critique of Practical Reason. trans Lewis White Beck, 1956, p. 166]. Rational moral agency is what makes moral autonomy possible, for Kant. Moral autonomy is the highest known form of psychological agency. A morally autonomous individual is one who directs his or her own voluntary behavior in accordance with an internalized conception of the moral law. The term "autonomy" literally means "living by ones own law" or "giving law to oneself." The autonomous individual is one who is capable of independent moral judgment and decision-making and whose will is directed by their own moral conceptions and rational judgments, not by the will of another or by instinct or emotion. As John Christman writes, "Put most simply, to be autonomous is to be one's own person, to be directed by considerations, desires, conditions, and characteristics that are not simply imposed externally upon one, but are part of what can somehow be considered one's authentic self." ("Autonomy in Moral and Political Philosophy"). The concept of moral autonomy plays a central role in liberal social and political philosophy as well as in normative ethics. One must, however, distinguish among various senses in which the term "autonomy" is commonly used, for instance, between basic autonomy which is the moral status in which the individual has the capacity to make their own decisions and speak for themselves, and be held morally accountable for their actions, and ideal autonomy in which a person is maximally authentic and free from all forms of distorting influences on their judgment. For this discussion, I will be using the term "autonomy" in the basic sense, though I want to emphasize that even in this sense, autonomy is a personal achievement.
As Warren points out, Kant held that moral agency is both a necessary and a sufficient condition for full moral status, while she, and many other philosophers, including myself, who have thought about this question, strongly doubt that it is a necessary condition. On the view I have been discussing, there are at least three levels of moral standing: one for living, non-psychological organisms, another for living psychological organisms, and a third for living rational moral agents. So on my view, while moral agency is not necessary for a being to have moral standing, it is sufficient.
Additionally, on my view, being a moral agent or rationally autonomous is not a necessary condition for being capable of holding rights; some moral patients who are not also moral agents, are capable of being ascribed rights based upon their psychological agency. But while moral agents can also function as the objects of obligations, and can also be the holders of rights, moral obligations can only be meaningfully ascribed to moral agents. Only autonomous moral agents, those with full moral agency, are ascribed full moral responsibility for their behavior.
There is a problem, though, in deciding when something qualifies as a moral agent. Predictably, philosophical opinion on this question divides between those who favor a minimalist and a maximalist view. Kant and Locke were minimalists who argued that moral agents must be capable of being held morally and legally accountable for their actions, and that therefore, only normal human adults qualified as moral agents with full moral status. Human infants and young children, persons with some kinds of severe mental disorders or disabilities, the comatose, and sentient non-human animals, would, on this view, be excluded from the category of moral agents.
Other philosophers have noticed that even some animals seem to know the difference between "right" and "wrong" and exhibit some of the psychological capacities necessary for moral agency. Your dog probably know that it is not supposed to urinate on the carpet. While not, strictly speaking, a moral wrong, the fact that dogs can be trained to avoid behaviors which their human masters find distasteful, seems to indicate that they are capable of at least some limited form of moral agency. Research on primates, by Franz de Waal, and others, strongly suggests that some apes possess a sense of justice. Many animals exhibit behaviors like caring for their young and defending them against predators that seem to us to be moral responses indicative of some degree of moral agency.
For instance there is a documentary film about a group of African elephants that adopted an orphaned calf (as described in Ingfei Chen,"The Social Brain" Smithsonian Magazine June 2009, pp. 38-43):
When the baby elephant falls into a water hole, the matriarch quickly marches in, followed by the others. Together she and a second female use their tusks, trunks and legs to free the calf from the muck. Another animal paws at the steep bank with its foot, building a ramp the youngster uses to climb to safety. "It's really remarkable...," how the elephants rapidly sized up the crisis and worked together to save the baby. "It's a very high sort of functioning that very few animals are able to do....humans can do it only on good days."The case is reminiscent of the famous example from Peter Singer in which a small child falls into a shallow lake and a passerby must decide whether it is worth ruining his good shoes to wade into the water to rescue him. On good days, presumably, the answer is he should.
John Rawls attempted to solve the problem of defining the range of moral agency by proposing that we think of moral agency is a "range property," that is, being capable of having a sense of justice or a conception of moral obligation or being accountable for one's voluntary actions, is a complex set of psychological capacities which different individuals may possess in differing degrees. This allows for us to use the term "moral agent" in a maximalist way to describe young children and some non-human animals, who possess some, but not all, of the psychological capacities necessary for full moral agency at least to some degree.
While I am comfortable with this suggestion, I think we will still need to have another concept, that of "full moral agency" or "moral autonomy" to designate those kinds of individuals which have these capacities in sufficient measure as to make them fully accountable and morally responsible for their behavior. Full moral agency, moral autonomy, is a moral status that not all moral agents, nor all human beings, ever achieve. Only those individuals who have attained full moral agency can be held strictly accountable, morally speaking, for their behavior.
Young children are generally not accorded full moral status because the degree with which they are in control of their moral faculties is insufficiently developed. We exempt young children from criminal liability for certain kinds of moral or legal wrongs they may commit, or if we do hold them accountable for them, do so with their immaturity functioning as a mitigating factor in ascriptions of blame and punishment. Children are not yet morally autonomous moral agents, and one way to understand this is to recognize that paternalism is justified when children are concerned. Parents should sometime override their children's wills when doing so is in the child's best interests. Children cannot give consent for medical procedures in their own names; they cannot be parties to contracts, and they cannot vote. Children develop moral competence though the process of socialization, and if all goes well, they do eventually attain adulthood and so achieve the moral status of full moral agency and become autonomous moral agents. Children grow in moral stature as they acquire the complex set of psychological capacities necessary for full moral agency or basic moral autonomy, but they can be considered to be moral agents, albeit novice or immature ones, before that time, at least once they have sufficiently developed linguistic capacities so as to allow them to be capable of "giving an account" of their actions. Thus, I agree with Warren when she writes, "Without a language that is capable of representing moral concepts and principles, real moral agency is not possible" (p. 161).
By "real" here I think she must mean "full", since elsewhere she suggests that some non-linguistic animals exhibit some of the characteristics of moral agency. In any case, I see no problem in using the term "moral agency" in both the maximalist sense and in the more restricted minimalist sense of individuals who have attained full moral agency or moral autonomy, so long as it is clear which sense is being employed.
But, on my theory, being a moral agent, to any degree, is not a necessary condition of being capable of holding rights, so even infants, and probably also human fetuses who have developed to the point of psychological awareness, can be ascribed meaningful rights, whether or not they are also considered to be moral agents. So can intelligent social animals such as elephants, whales, chimpanzees, dolphins and other categories of psychologically complex animals.
Another noteworthy feature of my view is that some kinds of organizations, such as corporations and governments, can be ascribed full moral agency, even though they are not living beings. Corporations can have both rights and obligations even though they are not alive and do not die. Organizations which have centralized internal decision-making structures, operated by human moral agents, can be ascribed a kind of moral agency which is not reducible to the agency of their human operators. Corporations and governments can be held morally and legally accountable for their actions. I will discuss this matter in greater detail at a latter stage in the argument, but for the time being, I wish to indicate that moral agency, even full moral agency, is not in my view a grade of moral status that is reserved only to living normal human adults. It is also conceivable that alien creatures, such as E.T. or the Vulcans from Star Trek, should be regarded as possessing full moral agency, and similarly, advanced intelligent robots and androids, such as "Data" will be considered to qualify for full moral agency, where this means that they can be treated as the bearers moral obligations for whose fulfillment they can be held fully morally and legally accountable.
Entities that have the moral status of full moral agency, or autonomous moral agents will also by that token be the holders of rights. Full moral status is a sufficient condition of being a right-holder on my view, because as I will demonstrate later on, being the bearer of moral obligations, such as the responsibility to protect the vulnerable, entails that those moral agents who have them must also have at least some rights. This conclusion will follow on the supposition, which I will also address later, that the status of full moral agency has moral content, that is, full moral agency or moral autonomy carries with it certain substantive moral responsibilities. Put another way, full moral agency functions as both a necessary and a sufficient condition for having certain kinds of moral obligations.
Moral agents that have attained full moral autonomy have also a kind of inherent value which is distinct from the inherent value of living things, and psychological organisms, though when the moral agent in question is a living adult human being, she or he also possesses these other kinds of inherent value. Kant thought this this was the only kind of intrinsic moral value, but, I have explained why I disagree with this view. However, I will continue to employ Kant's term "dignity" to refer to the specific kind of intrinsic moral value that living, sentient, moral agents that have attained full moral agency or autonomy possess. Artificial moral agents, such as corporations and robots, do not have "dignity" in this sense. Living sentient alien species who are capable of being treated as full moral agents, will probably also have this kind of inherent value, but since we do not know of any such creatures, we can defer this question as speculative at this time.
Adult human beings who possess the usual complement of developed psychological capacities necessary for full moral agency or moral autonomy, and who have been sufficiently socialized so as to understand the concept of moral duty, have "dignity" because they are not only capable of having moral obligations, but because they actually do have them, and as a consequence of having moral obligations, also must have certain rights. Thus, having dignity is a sufficient ground for having rights. But, as I have emphasized it is not a necessary condition for having rights. There can be, therefore, things whose moral standing makes them capable of being ascribed meaningful rights, but which do not have the status of fully competent moral agents.
Thus far in this discussion I have avoided using the terms "person" and "personhood." These terms have been the topics of extended philosophical controversy, as Warren's discussion in Chapter 4 of her book, attests. My use of the term "moral agency" tracks many of the key features of the ways in which philosophers have wanted to use the terms "person" and "personhood." On maximalist view of personhood, any entity that exhibits some of the capacities associated with moral agency to at least some degree, can be considered to be a "person," even though they may not have attained the standing of autonomous moral agents. On a minimalist view, only entities that have attained full moral agency or basic moral autonomy, can be called "persons." But this is too restrictive since it would imply that human individuals do not become persons until they graduate from high school.
Using the maximalist sense, a intelligent adult chimpanzee who has been taught to use signs to communicate with human beings, can be regarded as a person, and so can young children, and certain categories of human adults with impaired psychological abilities, such as those with advanced dementia. Corporations are also regarded as "legal persons" and should also, I believe, be regarded as moral persons with respect to their social responsibilities and other sorts of moral obligations which they can possess. Governments, and some other kinds of organizations with centralized internal decision-making structures, would also be legal and moral persons in this sense, albeit non-living, artificial ones.
However, corporations, governments, chimpanzees, dolphins, intelligent androids, and extra-terrestrial life forms, are not human. The question to which we must not turn our attention is whether or not being human confers upon an entity some additional moral stature.