R: Never Trust a Consequentialist

It has become terribly démodé to call oneself a utilitarian, but "consequentialism" is quite alright. This moral theory promises real good for society because it allows choices to be evaluated according to the goodness of their actual results. But when it comes down to it, can you trust a consequentialist to keep a secret? Can such a friend be depended upon to follow through on a promise and defend your honor when you are away? It is perhaps more likely that he will eventually betray your friendship to achieve some "good" result. Can rule consequentialists be trusted more often than their act consequentialist brothers? How do we determine if a result is good, anyway?