The bad-good axis is a mapping of the overall result of a moral evaluation, i.e. a determination of how good or bad an action is as seen by a given moral system, which specifies criteria for evaluating actions.
Policy decisions (i.e. those affecting more than just the decisionmaker) are best made through evaluation of the relative goodness or badness – costs vs. benefits – of each of the alternatives, so that the decisions reached will, on average, bring the most net good (i.e. [total amount of good] minus [total amount of bad]). This process holds true regardless of how you measure or define goodness and badness, though obviously different moral systems will arrive at different answers because of different goodness/badness levels each system will assign to the expected outcomes of each possible decision.
In practice, of course, there are uncertainties and multiple goals (or moral values) which usually make it very difficult to come up with one final "net goodness" value for each possibility so that they can be objectively evaluated against each other.
I'm not sure yet, but it looks like moral absolutists take the position that "evaluation of costs vs. benefits" cannot be a basis for evaluating the morality of an act because it equates to saying the end justifies the means. This only makes sense if you exclude the harm done by the "bad" act itself; e.g. if you hold that action X is extremely wrong and outweighs any possible good which might be accomplished by doing it, then by definition your evaluation of any instance in which action X was used to accomplish something good would be that the net result was still extremely bad. The process still applies; only the values are different. --Woozle 21:34, 16 August 2006 (EDT)
Addendum: On the other hand, it is very easy to overlook the harm done simply by the act of "breaking a rule"; if this harm is excluded, then an "evaluation of costs vs. benefits" may very well equate to the end justifies the means. For this reason, it is important not to oversimplify such evaluations. --Woozle 20:52, 1 September 2006 (EDT)