Meta-ethics is a set of theories about doing ethics. Ethics, considered broadly, is a normative theory about the nature of the moral life or the moral realm, that is, the realm in which we talk about things like values, duties, rights, virtues, responsibility, blame, guilt, and a variety of other moral concepts. Normative ethics is that branch of ethics that attempts to explain morality, that is, roughly, to give an account of what it is moral agents owe to one another as members of a moral community. I say roughly, because as I will define the notion of a moral community, it will include as members moral patients who are not also moral agents to whom (or to which) moral agents owe moral responsibilities. Morality concerns what it is we should do, and normative ethical theory attempts to give a systematic answer to this question.
The leading candidate for this status is the principle of utility, particularly that version championed by John Stuart Mill, known as the Greatest Happiness Principle. According to this theory, what is morally right for moral agents to do is to act so as to maximize that happiness (or well-being) of all of those (sentient) individuals who are affected by our actions in the long term counting each individuals interest in happiness as equal. This is sometimes referred to as the ethics of universal benevolence. The principle of utility has many variants and many defenders, so many, that I do not have time to review them here. I want to focus only on that group of utilitarians who join this principle of normative ethics to the assumption of theoretical monism, that is, the idea that there is only one fundamental principle of ethics. It is this idea that I want to reject.
Instead, on my view, there will be a plurality of fundamental principles of normative ethics that together describe and explain the moral intuitions that normal, morally sensitive individuals have over a wide range of cases and contexts. In some cases and in some contexts, utility provides a useful moral guide to what conscientious moral agents ought to do. But it is not the only guide to normative rightness and must give way in certain kinds of cases to moral considerations deriving from other fundamental moral principles.
One can appreciate the pluralism of normative ethical principles by focusing on the nature of the arguments that are commonly employed against utilitarianism when it is cast in the role of the master principle of ethics. One finds counter-intuitive examples in which considerations of utility conflict with those of justice, for instance, in the case of the drifter who can be framed for a crime he did not commit. Or arguments involving conflicts between the duty to maximize impartial utility and duties of care that arise because of special interpersonal relationships. Or cases in which the duty to respect personal autonomy runs up against a attempt to do what ones knows to be in another person's best interests. In all of these kinds of arguments the basic structure consists in noticing that the duty to maximize utility conflicts with some other kinds of moral obligations derived from some other moral principle.
The current global consensus on human rights is a good example of this kind of "many-legged" justificatory strategy. Human rights norms and values are justified by a variety of different sorts of moral and practical considerations deriving from considerations of justice, utility, nonmalefiecence, vulnerability, dignity, equality, convention, as well as by religious or metaphysical and metaphysical beliefs. There is no such thing as the justification for human rights. Rather there are a set of partially adequate overlapping justifications for various particular rights as well as a general set of philosophical and political rationales for holding that certain rights should be regarded as belonging to persons as such, irrespective of their particular identities. (See Morton Winston, "Human Rights as Moral Rebellion and Social Construction." Journal of Human Rights, Vol. 6, No. 3 2007: 279-305. for a fuller account).
A plurality of principles also enables us to achieve a better fit between our principles and our moral intuitions over a wide variety of kinds of situations and issues calling for moral reflection and decision. No single moral principle can do the job of describing our actual patterns of moral judgment as well as a set of multiple moral principles. It is not just that normative ethics is just a "messy" field of inquiry that has not yet achieved its true paradigm -- the moral life is just too complex to be reduced to a single over-arching theory of what makes actions morally right, what makes some things morally valuable, and what the good life for human beings consists of.
But because the VCP is a relatively under-studied principle of ethics, one whose theoretical value and importance is not widely understood or appreciated, I think it worth emphasizing it in order to reveal its potential. In my view the VCP is not just as a normative principle that can be used in the private sphere of the family, where it finds it most natural home, but also in the public sphere whether it is often considered not to apply at all or to apply in only limited ways.