Previously I addressed the question of whether (assuming we are consequentialists) we must determine which rules guarantee the best outcomes, and then follow them, or if we instead should simply look for the action that yields the best result on a case by case basis. I concluded that no matter what rules we might develop there could be situations in which following them would yield a less then optimum result, a result that simply looking for the best outcome might be able to achieve, assuming you appropriately account for the behavior of other people. And thus that we should decide what to do on a case by case basis, because that method yields the best results (applying consequentialism to how we should be consequentialists).
This addresses the theoretical argument for developing and following fixed rules of behavior. But there is also a practical argument for developing and following rules. Practically speaking we don’t have the capability to analyze each situation we find ourselves in. Sometimes we simply don’t have enough time, and sometimes we don’t have enough information. Thus, the argument goes, we should establish and live by rules because by doing so we will achieve better outcomes than the person who must reason about each situation (as they often fail to act in a timely manner).
I think this argument for rules is a good one, but accepting this practical argument is not the same as embracing the theoretical argument, which would have led to a kind of deontology. Instead you would be following the rules because you think they will lead to the best outcome in your current situation (because you know that they generally lead to good outcomes), and not because you have a general obligation to follow the rules.
But isn’t this vulnerable to the same problems that the theoretical argument for rules ran up against, that in some situations following the rules will result in undesirable outcomes? I do not think it will, because people who approach ethics in this way keep in mind that their first obligation is to ensure the best outcome, and not to follow the rules. This means that if you find yourself in a situation where the rules seem to be leading to a bad result it is ok to break them, in fact it is required that you break them. And I think most people are capable of figuring out when this is the case. Generally speaking the ethical rules that are formed for practical reasons are meant to cover the average everyday situations. Thus when you find yourself in an unusual situation, one that was not in mind when your ethical rules were being thought up, then it is possible that your rules may mislead you.
For example, one obvious ethical rule we could come with is: “don’t torture people”. We realize that societies that endorse torture are societies that quickly become filled with fear, societies that give their governments too much power. Such societies inevitably collapse. Thus torture leads to outcomes that are undesirable (the collapse of society), and so we endorse the rule saying not to torture people. But then let us say that you find yourself in an exceptional situation, where some madman has set up a bomb to destroy the world. Is it ok to torture him to discover how to disarm it, assuming there is no other way? Probably, since one precedent of torture is a better outcome than a destroyed world. But this does not invalidate the rule, the rule is a good one, and still must be followed in the majority of situations.
Another example of rule we might endorse is: “don’t take things being sold without paying (don’t ‘steal’ them)”. However, this rule is formed with physical objects in mind. And I would contend that when we extend that rule to cover things like data we are extending it beyond the cases it was designed to cover, and beyond where it is appropriate. But I have already spelled out my arguments about that here and here.
In summary: developing and following ethical rules is usually a good idea, but following those rules without exception is a bad idea. In a way this is a kind of common sense morality, since I suspect most people already approach ethical rules in this fashion (or at least I hope that they do).