Rule Theory
Some people argue that the moral rules come from God, and that we know the rules through revelation. This defense provides a religious, not philosophical, view of the origin of moral rules. Philosophically, the view is problematic. Many religions exist and have different accounts of revelation, appeal to different sets of rules, and interpret rules differently. Philosophical problems stem from the fact that many religions claim support for different rules by appeal to the same source: God's will. The ultimate appeal is often to faith, although faith may be backed by philosophical argumentation. But philosophy, by its nature, is willing to question faith.
Because of the variety of different and conflicting beliefs about what God wills, some believers must be wrong even though they have faith in what they believe. This does not mean that faith is always mistaken. However, philosophers also argue that if God wills specific moral rules, we would still be under obligation to question whether those rules were proper. Suppose God is evil and wills evil rules. How can the sole fact that God wills them make them the proper rules? A religious orientation would reject such reasoning; because God is all wise and all good; anyone who believes God's commands are evil would be wrong. Our wisdom and our goodness pale in comparison to God's. Again, this view, which may be correct, appeals to faith, and not to philosophical argumentation.
Cultural relativists believe that rules come from social practice. From a global perspective, this would make moral rules arbitrary; different people in different places would have different rules based on some accidental past circumstances, perhaps including the will of a dictator. But philosophers doing rule theory believe that moral rules serve basic functions. So although rules may diverge from society to society, they may be judged within a society by the extent to which they coordinate social activity, or by the extent to which they are stable, supported, and genuinely express the character of a people. Under this view, we know what the moral rules are by examining a society's practices. However, cultural relativism does not adequately deal with cultural conflict. Furthermore, moral rules are usually considered to be universally binding, so a defense based on local culture seems to be inadequate.
Another view about the origin and support of moral rules is that moral rules are best grounded in human rationality. If we have a solid conception of what is rational, we may be able to use that view to formulate a set of moral rules. Each person has constraints -- limited time, limited money, limited talent. Given those constraints, rational people try to get as much as possible of the things they prefer. This definition of rationality, optimizing one’s preferences, may preclude the existence of an acceptable set of moral rules. Why should people support rules that limit the extent to which they can get what they want? Why not steal, or even kill, to get what we want? Nothing in the standard definition of rationality says that we should not do those things. The contemporary American philosopher David Gauthier argues that this perception is mistaken. We do need each other's help. We do need to cooperate. (He thinks that the Prisoners’ Dilemma proves this.) If moral rules help us to cooperate, and thereby help us to get more of what we want, then rational people would be willing to be bound by rules. This is so even if, on a special occasion, more could be gained by breaking the rules. However, we all know that others may gain by breaking rules, so we may all rationally decide to bind ourselves, in advance, to rules, because in the long run this may be the way to get more.
Another defense we examine claims that no adequate reasons can be given in favor of the moral rules. We simply know, perhaps by intuition or even by social conditioning, that a rule is proper. That promises should not be broken is self-evident. If someone argues that keeping promises is not rational or that better consequences follow without the duty to keep promises, we may respond by saying that we have a self-evident duty to keep promises. That is, by careful reflection on what we believe, we will understand that we are more convinced of this duty than we are of the reasons offered against it, or, indeed, offered in its favor.
As you might expect, many philosophers (include all of those influenced by Peircean pragmatism) reject self-evident or intuitive support for moral rules. Intuitions differ from person to person and if they exist, may be socially caused. Yet we do have strong beliefs that we cannot adequately defend.
In the end perhaps the best defense of a list of moral rules is the fact that many people, at different times and places, have accepted such rules as a basic part of moral experience.
Yet another defense of moral rules might be thought to come from moral principles, but this defense would undermine the autonomy of the moral rules. (Think of how that would go.) We have been examining a rule approach to morality, one that rejects the use of basic principles. A rule-oriented approach accepts rules as the foundation of moral experience. However, some approaches combine the use of rules and principles; thus, rules might be supported by principles but cannot be fully derived from them.
How far did we get on that?