If one is in a moral quandary it is wise to look for ethical guidance if one has the time to do so. Ethical theories are, among other things, intended to be one possible source of ethical guidance. If such guidance is valuable, then in ethics there is an embarrassment of riches: There are multiple, well-accepted, yet mutually inconsistent theories. These include utilitarianism, Kantianism, virtue ethics, contractarianism, libertarianism, natural law theory, some forms of moral particularism, and more. The disquieting thing is that, at present, it seems that we are not at all close to being able to determine which of them, if any, is right. How can you know what you should do when ethicists, those who devote their careers to studying such theories, cannot reach a consensus on which one we should accept? Those who look to ethical theories for ethical guidance are apt to be disappointed. This situation is problematic, for if ethical theorizing is to have relevance to real-world ethical behavior, and not just be a way of examining ethical issues out of a love of arguments or puzzles, it must be possible for us to use ethical theories to inform ourselves of what we should do.
It seems that philosophers have usually tried to address the issue of how one should act by advancing arguments for or against these theories (or certain parts of them). I want to approach this issue from a different angle. The question I will address is this: Can you get ethical guidance about what you should do in certain situations without knowing, or even having good reasons to believe, that any particular ethical theory is right?
I know of at least one philosopher who thinks you can. In the following passage from his article “Hunger, Duty, and Ecology”, which was the inspiration for the ideas I express in this article, Mylan Engel Jr. rebuts an objection to the obligatoriness of donating to famine relief:
One of the most common reasons that I have heard philosophers give for rejecting the arguments of Singer and company [for contributing to famine relief] runs roughly as follows:
Singer’s preference utilitarianism is irremediably flawed, as are Kant’s ethics, Aieken’s theory of human rights, and Rawlsean contractarianism. The literature is peppered with devastating objections to these views. Because all of the aforementioned arguments are predicated on flawed ethical theories, all these arguments are also flawed. Until someone can provide me with clear moral reasons grounded in a true moral theory for sending large portions of my income to famine-relief organizations, I will continue to spend my money on what I please.
Such a self-serving reply is both disingenuous and sophistical. It is disingenuous because, as noted earlier, utilitarianism, Kantian ethics, human rights-based ethics, and contractarianism are among the most widely accepted theories in normative ethics. In other contexts, philosophers typically embrace one of these four theoretical approaches to ethics. It is sophistical because a similar reply can be used to “justify” or rationalize virtually any behavior. Because no moral theory to date is immune to objection, one could, for example, “justify” rape on the grounds that all of the arguments against rape are based on flawed ethical theories.
The speciousness of such a “justification” of rape is obvious. No one who seriously considers the brutality of rape can think that it is somehow justified / permissible simply because all current ethical theories are flawed. But such specious reasoning is often used to “justify” allowing millions of innocent children to starve to death each year. [footnote omitted] (Environmental Ethics, p. 462).
Engel goes on to justify his conclusions about donating to famine relief by appealing to what he takes to be almost universally shared commonsense beliefs about morality.
My approach will be different. My idea is that if you compare all the viable ethical theories that you know of, and find that all, or at any rate a great majority of them agree about whether an action you're considering is right, wrong, or permissible, then you know that it is at least highly probable that that action really is right, wrong, or permissible. For if all ethical theories agree about the moral status of an action, it can only fail to have that status if they are all false. And if a great majority of ethical theories agree about the moral status of an action, it can only fail to have that status if all of the theories that agree about its status are false, which becomes more and more improbable as the number of the theories that agree increases. Note that I’m not arguing that if a great majority of ethical theories agree about the moral status of an action then it automatically follows that it very probably has that status. The argument is rather that if some ethical theory or other is true, then majority agreement implies that the action very probably has the moral status that the majority of theories agree that it has. The upshot is that my approach should be a good guide as to what you should do as long as some ethical theory or other is true. So by using my approach you can be guided by ethical theories without having to attempt the difficult task of determining which of them is right.
To clarify, my idea is not to put different ethical theories together to get a composite theory, but to help someone figure out what they should do in a fairly specific situation. By comparing different ethical theories you might find that they agree about what you should do in a situation, but they might not agree about why you should do it. If you try to “combine” the guidance you get across diverse situations the result would probably not be cohesive enough to yield an ethical theory. And if you find that a sufficient number of ethical theories don't agree even about what you should do in a given situation, I think the most you can conclude is that you don't know what you should do, and in such a case you would not have any determinate guidance. So I think that in some cases my approach will give you guidance and in other cases it won't.
Nevertheless, on my view, you would have a reason to explore as many different candidate ethical theories as you can, even though there is no need to determine which of them is right. This is because the more of them you consider, the more certain you can be that you have a representative sample of all the possible viable ethical theories, and the more representative the sample is, the more certain you can be that an action really has the moral status you think it does given that the majority of ethical theories agree that it has it.
It is important to note that ethical theories properly so called need not be the only kind of ethical view that one might have to take into account on my approach. Timothy Chappell has introduced the different yet related notion of an ethical outlook, which he characterizes as follows:
Anybody who is going to live a genuinely worthwhile and a fully human life will have to live out a set of views and commitments about the central questions concerning value: what is worth living for and what is worth dying for, what is really admirable and what is really contemptible, what we must do at all costs and what we must not do no matter what; and so on. This set of views and commitments need not be very explicit; but it must run deep—must be sincerely and indeed passionately held. And it need not be very systematic; but it must be as considered, rationally defensible, and coherent as possible. Any such set of views about value is what I will call an ethical outlook.
The notion of an ethical outlook is, in principle, broader than the notion of an ethical theory, for it can include ethical theories as well as ethical views that are less systematic. In Chappell’s opinion, mainstream ethical theories are not credible ethical outlooks, because he thinks they are ill-suited for any of the four roles that he regards as important ones important for ethical outlooks to play. I am not convinced by his arguments, but I don’t have the space to address them here, so I will proceed on the assumption that mainstream ethical theories are credible ethical outlooks and leave the analysis of Chappell’s arguments for another occasion
Given that there may be ethical theories that have not yet been thought of by anyone, it is not certain how many of them there are. But it is certain that not all of them are created equal. Thus, in order to carry out a project like mine, it will be necessary to develop criteria of viability that one can use to eliminate theories that are inadequate and thus narrow down the range of theories one will have to consider. In this section I will list some of these criteria.
One criterion is cohesiveness. Ethical theories cannot contain contradictions, but more than that, their components must be mutually supporting and fit together well. That is, an ethical theory can’t just be some arbitrary set of statements about what one should do that happens to be logically consistent. Some parts of the theory must provide a rationale as to why such-and-such is right, wrong, or permissible. Furthermore, these parts and their rationales must be subsumed under some common principles, or be such that relevantly similar actions receive relevantly similar evaluations, and for relevantly similar reasons.
Another criterion is comprehensiveness: An ethical theory cannot merely tell one what one should do in just a few cases. It should give one guidance that applies to a large number of cases of various kinds.
An ethical theory also has to have verifiable implications for one’s behavior. That is, one’s obligations must be such that it is in principle possible for one to discover what they are if one makes the effort to do so. If an ethical theory says, for instance, that in cases having feature F one should do x and in cases having feature G one should not do x, there must be a way for one to recognize that one is in a case which has feature F or a case which has feature G. If this were not so, one could only do x or fail to do x in the appropriate kind of case through a lucky guess. Even if one assumes that one really would have obligations in such a skeptical scenario, it would be pointless for one to try to find out what they were.
Yet another criterion derives from the old but venerable principle that “‘ought’ implies ‘can’”. Ethical theories must be psychologically plausible: One cannot be obligated to do something if it is psychologically impossible for one to do it. And if doing something is possible but difficult, an ethical theory which prescribes doing it is less viable the more difficult it is to do it.
As with any kind of theory, ethical theories should not contain any statements that have been shown empirically to be false. They should, in other words, be empirically adequate. This seems obvious enough, but if one takes one’s theorizing seriously it requires that one should make the effort to see if the ethical theories that one is considering are consistent with any relevant scientific theories or bodies of knowledge.
The guidance that an ethical theory provides must also be appropriately specific, that is, it should not be so vague that it doesn’t really recommend anything in particular.
Finally, however specific an ethical theory’s guidance may be, when considering it one needs to ask oneself, “Do those who know this theory best agree about what it recommends and what it doesn’t?” The more difficult it is for the relevant experts to agree on how to interpret the theory, the more it lacks interpretational stability and the less viable it is.
I will make no claim that the above list of criteria is complete, but one has to start somewhere. However, I will claim that these criteria are both necessary and useful for my project.
To read the full article, please go to Scholardarity.com, How to Know What Should Be So: Ethical Guidance and Ethical Theories.
 “Ethics Beyond Moral Theory,” p. 7.
 Chappell actually uses the expression “moral theory,” which I take to be equivalent to the expression “ethical theory” as I use it.
 Here is Chappell’s characterization of these roles:
We want our ethical outlook to be something which, in real time, can be the source of our reasons to act (motivation), and which can structure our thinking and deciding about how to act as it actually happens (deliberation). We also want our ethical outlook to be something which, offline, can articulate and deepen our understanding of what counts as good or bad and right or wrong action, and why (explanation); and we want it to be something which can explain what will or would be good or bad and right or wrong action, in future or hypothetical situations that we ourselves have not actually met, but which we or others might conceivably meet (prediction) (“Ethics Beyond Moral Theory,” pp. 12-3).