Many of the standard ethical thought experiments that philosophers use to elicit strong moral intuitions are ones that employ some kind of threat that makes the moral patient seems specially vulnerable. For instance, in the ever popular trolley examples, the scenario always involves some people who are tied to trolley tracks and are in danger of being run over by a trolley. Individuals who are tied to trolley tracks are unable to flee to avoid the on-rushing trolley and so are specially vulnerable to being harmed or killed. It is the present danger that makes this kind of case so compelling as an example for the duty to rescue. One has a completely different response if the stipulation that they are tied to the tracks is omitted. Suppose that there are five people who are merely standing in the path of the trolley, but who are perfectly capable of moving off the tracks as the trolley approaches. Suppose on the other track there is a person who is lying unconscious across the track. In this case, I would not suppose that many people would opt for directing the trolley towards the one who is specially vulnerable -- the unconscious one. It would be assumed that the five others can protect themselves from the trolley by merely stepping to one side of the tracks, and so the moral agent should send the trolley toward them on the assumption that it would be preferable to risk hitting five people who can avoid being hit than it would be to surely kill the one specially vulnerable individual. The special vulnerability of the people on the tracks is a feature of this familiar case that is rarely remarked upon by commentators.
Or consider Peter Singer's famous case of the small child drowning in a shallow lake. The child in this scenario is specially vulnerable in the way in which, for instance, another child walking quietly on the shore beside the lake is not. One would not, I expect, be inclined to think that one has a special responsibility to rush over to the later child and warn him not to go into the lake where he might drown. He might well be equally vulnerable to drowning, in the general sense, but because he is not immediately threatened with drowning the special responsibility to protect the vulnerable is not triggered where it would be in the case of the child who is actually floundering helplessly in the water. Again, the scenario works to evoke the moral intuition that bystanders have a special responsibility to rescue the floundering child precisely because she is in a circumstance which makes her specially vulnerable.
There are other famous philosophical arguments that trade on the special vulnerability of a moral patient. Hobbes, for instance, in describing the "state of nature" makes it abundantly clear that persons in the state of nature are vulnerable to a great many harms, such as being killed in their sleep. But in discussing the right to life, he stipulates that it comes into play in cases where one's own life is actually being threatened. In such cases, he argued, we have a right of self-defense that allows us to act so as to protect our own lives, even if this means killing an aggressor. Indeed, for Hobbes, the right to life is the most fundamental and the only natural right we have, and we do not lose it even when we enter into civil society and live under the rule of a sovereign monarch; we would still in his view have the natural right to defend our own lives when mortally threatened by the King.
As Goodin explains it:
According to the Oxford English Dictionary, something is "vulnerable" if it "may be wounded," either literally or figuratively; it is "susceptible of injury, not proof against weapon, criticism, etc." Essentially, then the principle of protecting the vulnerable amounts to an injunction to prevent harms from befalling people. Conceptually, "vulnerability" is essentially a matter of being under threat of harm; therefore, protecting the vulnerable is primarily a matter of forestalling threatened harms. (Goodin, 1985, p. 110, italics added)In the Vulnerability Relation, the C term, is the condition or circumstance that constitutes the threat which makes a moral patient specially vulnerable. Goodin mentions infants and young children as classes of moral patients who are specially vulnerable (p .33). Also the mentally and physically handicapped, the poor, the aged and infirm (p. 34), terminally-ill cancer patients (38), American Indian tribes (40), refugees and stateless persons (168), and he suggests in passing, animals and future generations (169). I will develop and defend this suggestion at a later stage of the argument, but for the time being, it should be clear that when I use the term "vulnerability" I will mean actually being under threat of harm, rather than just the abstract possibility of being harmed.
Given this meaning of vulnerability we should be able to say things like: members of an endangered species a vulnerable, while those of a non-endangered species are not. Prisoners as a class are vulnerable, while those not imprisoned are not. What makes prisoners specially vulnerable is the fact that their condition of incarceration removes the possibility of their defending themselves from threats by fleeing. This is one of the feature that make the practice of torture so morally horrendous -- the person who is being tortured is typically a captive who has no means of escape nor any means of defending himself from assaults upon his person. It is the deliberate infliction of pain upon a person who is specially vulnerable that make torture so appalling. As we shall see, many of the things that we call "human rights" are designed to forestall threats of just this kind, that is, threats upon persons who are, for some reason or another, specially vulnerable. Indeed, oppressed persons generally are an important class of specially vulnerable moral patients. If oppressed persons, as a class of moral patients, are specially vulnerable, and if the VP is a fundamental principle of ethics, then it follows that those moral agents who have the ability to protect the oppressed and prevent them from being harmed, have the moral responsibility to do so.
Under the VP moral agents who have some ability D to forestall or prevent oppressed persons from being harmed have a special responsibility towards them. This is, I believe, the ethical basis of the responsibility to protect that has recently been developed to articulate the requirement to aid those peoples threatened with genocide or ethnic cleansing. Bystander nations have the special responsibility to protect this class of specially vulnerable moral patients. As Goodin, insists, "What the vulnerability model emphasizes is not just their special need, ... but also your special ability to help. That is the crucial factor in imposing the duty upon you in particular" (p .34). This special ability to help is the D factor in the Vulnerability Relation. Moral agents who are incapable of helping the vulnerable can be excused from their moral responsibility to protect the vulnerable, other things being equal. But those who are able to help, and who have no other legitimate excuse, acquire an actual moral obligation to act so as to protect the vulnerable.
We can say that members of the class of moral agents who possess D occupy the role of a potential rescuers. To illustrate this notion, suppose that a fellow airplane passenger suddenly stops breathing while in flight. The persons who are that individual's potential rescuers include those trained in CPR or who have special medical knowledge that might enable them to render assistance. Another passenger, for instance, a philosopher who does not know how to perform CPR, does not have the relevant D factor in this case. The responsibility to attempt to resuscitate the stricken passenger falls more heavily on those who have the relevant D, than it would on someone who lacks that critical skill. The class of potential rescuers might contain the flight attendants, a physician or nurse who is on the plane, or another bystander who has been trained in CPR. While the incompetent philosopher also has a prima facie moral responsibility to rescue the stricken passenger, he may be excused from actually trying to help on grounds of his incompetence, particularly, if there are other, competent moral agents present who rightfully can fulfill the role of potential rescuers because of some special training, skill, or ability they possess.
Some people might find it odd to speak about roles in this context. We normally think of roles as being defined by social conventions, e.g., the roles of doctor, lawyer, teacher, parent, and so on. However, as Goodin suggests, and I will later argue, not all roles are conventionally defined; there are some moral obligations that are brought into being between moral patients and moral agents because of the Vulnerability Relation itself -- that is, because of their special vulnerability and your special ability to help. It is possible to think of these sorts of moral obligations as natural duties, where the term "natural" here should be understood as opposed to "conventional." The responsibility to protect the vulnerable, in cases where one has the ability to forestall an actual threat to their survival, well-being, or freedom, is an example of such a natural duty.
If there is such a natural duty to protect the vulnerable, then the vulnerable have the basis of a moral claim to social protection, that is, they have a right to it. In this way, natural rights (or entitlements) can be derived from natural duties. The VP and the Vulnerability Relation, then, might plausibly provide an account of rights that does not depend on seeing them as either transcendental "God-given" moral properties, nor as mere social conventions. Natural rights, on this view, are derived from the natural responsibility of the able to protect the vulnerable.
The notion of a natural duty here is meant to indicate that the Vulnerability Relation and the Vulnerability Principle express a kind of theoretically primitive notion of moral obligation, primitive in the sense that it is not derived from any other moral fundamental moral notions or principles. It expresses a moral axiom that can be used as the basis for developing an ethics of global responsibility.