Steven Weinberg is quoted as saying this:
With or without it you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion.
I have long maintained that this is, in fact, false. What you need for good people to do evil things is the combination of the belief that the end justifies the means, and an appropriate end. After all, if you hold this then you will do anything you need to in order to bring about that clearly and intrinsically valuable end, and so if you have to imprison a few people, enslave a few people, or even kill a few people, hey, it’s still justified.
Utilitarianism — which includes the recently popular usage of “Reduce suffering” — are, in fact, all about the ends. Every action you take is justified by the end it will produce, which in its case means that it promotes the most happiness — or the least suffering — for the most people. In fact, all consequentialist moral philosophies share that principle; what you do is justified by what it produces.
So it’s no wonder, then, that it is so very, very easy to produce cases where using Utilitarian or consequentialist moral philosophies ends up with the moral agent taking absolutely horrific actions that happen to work out with the “best” consequences by their definition: not only is there nothing in those philosophies to prevent it, they follow a model that’s prone to evil means/actions aimed at producing good outcomes. Deontological and virtue theories aren’t vulnerable to this, because they attach the moral significance to the actions or the agents themselves instead of to the outcome. An action is dutiful, and an agent is generous or brave, even if the actions don’t have the intended consequence.
Now, one of the reasons — I think — for the popularity of consequentialist approaches is that it’s easy to determine when someone else is acting morally or immorally. With the others, ultimately the only judge of my morality is me, since I’m the only one who has access to my internal states and motivations; only I know if I was acting selflessly or selfishly when I give that money to charity. Which, I suspect, is one reason why the new “scientific” crowd likes consequentialist theories so much; they dislike it when you can’t observe something from the second or third person view but have to get down to first person brass tacks. But in my quick ruminations of the subject I can’t see how to eliminate the tendency for evil actions in Utilitarian and consequentialist morality in an attempt to produce good. And I’d like to see some Utilitarians try to answer that question.