How we define value (and what is valued) has a major influence on the ethical system we are led to adopt. Often the reason given for acting ethically is because it promotes what is valued, and thus is normative. But what is valuable? Obviously there are many different opinions about this; one way to categorize these opinions is by what viewpoint value is considered from. Obviously there are different kinds of interests associated with different viewpoints, meaning that they hold different things to be valuable. And these differences give rise to different systems of ethics. One final note: here I am using the term viewpoint loosely; strictly speaking only conscious beings have a viewpoint, but here I am using viewpoint to describe any system or entity for which things might go better or worse (and therefore might be said to have interests), even if it isn’t able to be aware of those interests.
The most common viewpoint for considering what is valuable is the viewpoint of the individual person. What the individual wants is thus considered to be valuable. Now we can make a further distinction here, as to whether what the individual actually wants is valuable or if what they would want, if they knew all the facts, is valuable, but this is a minor quibble. And usually the individual is assumed to give the highest priority to his or her own happiness. Obviously an ethical system developed based on this notion of value will justify itself by arguing that ethics is to the benefit of the ethical person, which often reduces ethics to some form of enlightened self-interest.
The next viewpoint to consider is that of the average individual. Under such a viewpoint what is valuable is what is in the interests of the largest possible number of people. Utilitarianism is probably the most well known ethical system that rests on this viewpoint. Since we have moved away from pure self-interest it is harder to make this kind of ethical system seem appealing, but we might argue that it is the ethical system we would pick if we didn’t know where we would end up in society (the veil of ignorance argument).
But people aren’t the only entities that have interests. We could also see things from the viewpoint of society. Since societies don’t have minds it may be harder to see how they can have interests. But it is certainly the case that some societies are “healthier” than others, by which we mean they are more likely to survive as they are in the long run (for example, a free and open society is “healthier” than a dictatorship, even if the dictatorship his a larger army). Thus it is better for a society to be “healthy”, and so we can say it is in a society’s interest to be “healthy”; and thus what is good for society is valuable. The kind of consequentialism that I personally advocate is derived from this view of what is valuable. It is even harder to argue for this kind of ethical system then it is to argue for utilitarianism. One way to do so is to point out that we are part of society, and thus its, indirectly, in our best interests for society to survive, just as it is in a cell’s best interest not to be cancerous. We could also modify this viewpoint, slightly, to be that of the human species, or perhaps that of the planet as a whole. I suspect that the notion of what is valuable would be similar under them, but I know of no ethical system, offhand, that seems to be based on such an idea of value.
The above three are, I think, the “main” viewpoints, those from which ethical issues, and the idea of value itself, are most often examined from. There are, however, a few more “odd ball” viewpoints that I can think of. I don’t know of any ethical system that is tied to them, or any reason to favor them over one of the main three, but perhaps they might be useful. The first of these is that of a future person. Obviously the future person wants to live in the best future possible (the future that will make them the happiest), and thus they have an interest in things now because what happens now has an effect on what future will exist. We might also attempt to consider the viewpoint of the universe as a whole. Now this is a really odd idea, because it is hard to see how the universe could have interests, or how anything we do could affect them. Perhaps this viewpoint is behind nihilism? Another possibility is to consider the viewpoint of only a few select individuals. This could take a sinister form (e.g. valuing only what is important to the leaders or some other small group of people), or it might result in a perfectly altruistic ethics (valuing everyone’s viewpoint but your own). Finally I should mention a viewpoint that is not unheard of, but deeply un-philosophical, which is that of a divine being. Such is the attitude of many religions, that what is and is not valuable (and thus what is or is not good) is determined by the wishes of this being. Although there have been many people who have historically subscribed to such a position I say that it is un-philosophical because a) there is no way of knowing for sure what the divine being values, b) it is hard to see how a divine being could have interests, and c) it would make the divine being irrational, because there is no other criterion besides its will as to what is and is not valuable.
Of course the question remains as to which of these viewpoints is “right”. In fact I would be inclined to deny there is a “right” answer, since that seems to imply that there is some independent fact of the matter as to what is valuable, which seems unlikely since value is obviously our construction. But, on the other hand, I think there is a fact of the matter about which viewpoint ethics should be conducted from. I conclude that it is the viewpoint of society, since ethics arose as an institution for governing inter-personal relations for the benefit of society (or perhaps I should say that various pressures led to ethics based on such a viewpoint being established, in order not to imply that somehow society intentionally created ethics). But, you might say, actual ethical systems fall short of this goal. To this I would reply that ethical systems, as found in the “wild” are of course imperfect because there is no designer with the interests of society in mind behind them. However, since ethics only arises in societies, and seems obviously to exist to benefit those societies, I think it is fair to say that ideally ethics is the system that is best for society. Of course this is simply my position on the issue, and independent of approaching value through various viewpoints, I just couldn’t help myself.
See also: the good life (as what we value, and thus what lives we value, plays a central role in determining what we think of as the good life).