Sometimes the end justifies the means

One issue which crops up in Christian ethics is whether circumstances and/or consequences should ever figure in what we do, or refrain from doing. Joseph Fletcher was an Episcopalian priest turned atheist who wrote an infamous book entitled Situation Ethics. That has given "situation" invidious connotations in moral theology. 

But his misappropriation of the word no more discredits the moral relevance of circumstances than Thomas Altizer's The Gospel of Christian Atheism discredits "Christianity" or the "Gospel." They are not entitled to co-opt certain terms or categories. 

In Christian ethics, some actions are intrinsically good or evil. The outcome, however good, can't justify certain actions. 

However, that's not to say the end never justifies the means. Just that that's not a universally valid principle. Let's take two hypothetical cases:

i) Say my brother suffers from kidney disease. He needs a kidney transplant to survive. I'm a compatible donor. I'm young and healthy. My kidneys are in fairly pristine condition. Their natural expiration date is decades from now. 

All things being equal, I'd say have have a obligation to donate a kidney to my ailing brother.

ii) But that can be countered by extenuating circumstances. Maybe he suffers from kidney disease because he's an alcoholic. Maybe I'm the father of two young kids.

That changes the moral evaluation. Kidney donation isn't risk free. It entails some loss of kidney function. Likewise, if you donate a kidney, then develop renal cell carcinoma, surgeons can't simply remove the cancerous kidney. Like having a flat tire without a spare tire in the trunk. 

If my brother is already involved in high-risk behavior, do I have an obligation, or the same degree of obligation, to risk my health or life on his behalf? If his alcoholism has already destroyed his two good kidneys, what's the point of donating one of my kidneys? His lifestyle will destroy that organ.

Finally, if I had a wife and growing children, I have an obligation to them, to stay strong and health to provide for them. 

I don't think I have an obligation to donate my kidney under those circumstances. 

iii) Let's take another example. As a matter of professional ethics, paramedics and ER physics are required to be impartial in their treatment of patients. But suppose you have two gunshot victims. One is a five-year-old child. The other is head of a drug cartel. He's responsible for assassinating prosecutors and judges, bribing police, torturing and beheading police informants, &c. 

Is a paramedic or ER physician under a moral obligation to resuscitate him? Or is it proper to take the consequences and circumstances into account?

That isn't moral relativism. It isn't relativistic to distinguish between saving innocent life and saving the life of someone who takes innocent life.  

iv) Now, someone might object that my illustrations beg the question. Admittedly, I'm not using these two contrasting examples to prove the moral relevance of circumstances. Rather, these are ways of exploring our moral intuitions. Is it plausible to think circumstances should never figure in our moral evaluation?

As Christians, we benefit from having some revealed moral norms as well as some revealed examples. But, of course, that only takes us so far. There are ethical questions for which Scripture offers no specific answers–even implicitly. So at that point, intuition is all we have to fall back on. 

There are examples in Scripture where the end sometimes justifies the means, like Jesus healing on the Sabbath or Samuel dissimulating in his reply to Saul.