You are drifting in a lifeboat with another survivor of a shipwreck. The two of you have a single piece of bread left. Possible human behaviors are:
Where is morality in this picture? Most people would select the first scenario, breaking the bread into two equal pieces, as normal human behavior. It is true that human beings, even strangers thrown together, seem to fall very naturally into equal sharing of available resources, whether dividing up the last of the pate or taking turns on the swing at the playground. It is logical that equal division of resources gives the fewest grounds for protest or argument and puts the individual arguing for more in the position of appearing selfish.
Most people would also identify the individual who foregoes her slice of bread as a hero or saint, the person whom they aspire to be, though they know they are not strong enough.
The lifeboat scenario also illustrates the fallacy of conflating morality and necessity. It may be "necessary" to kill the weakest in order to survive, but it is not moral under any system based on equality, compassion or the value of all human life. From this insight, it is not a great step to the understanding that acts of war or of self-defense are not moral simply because necessary. If there is a moral distinction to be drawn between machine gunning some nasty Nazi attackers in Normandy and killing and eating your lifeboat companion, we have to look very closely to see it. Usually, it wouldn't even occur to us to spot any similarity between the two scenarios, but that is only because the "war heroism" scenario comes pre-loaded with value judgments: the attackers are less than human, or they are very bad human beings who deserve to die, and by killing them we are defending our own values and everything dear to us. But all the same arguments can be made for the lifeboat.
For example, I may consider myself a better human being than the weaker occupant of the lifeboat. Perhaps he is a thief or even a murderer. Simply by lying there weakly and groaning for help, he is making a claim on my time and attention which may lessen my chances of survival. Every mouthful he ingests is a mouthful that might have gone to strengthen me. The more desperate things become, the more he and I are competing for life, just the same way that American and Nazi soldiers facing each other in Normandy were competing for life. In both cases, "its either him or me," and whenever we say that, it is our natural conclusion that "it might as well be me."
One of my points here is that violence is never just, even when it is "necessary". Any act of violence to ensure our own survival cheapens us, makes us brutal and diminishes our potential as human beings, no matter how justifiable it is based on circumstances.
Violence usually is perceived as "necessary" when all law and social mores have broken down, or in momentary circumstances when they are considered inapplicable. In the scenario given above, I did not reveal the source of the bread. For some people, it may make a huge difference whether the bread was in the lifeboat's emergency survival kit (it was public property and should be shared) or in your pocket (it is your private property and may be hoarded). All the law has to say about your situation in the lifeboat is that you may not kill your fellow, no matter what happens. The law does not intervene in the question of whether you share or hoard your bread.
Your rationalizations for not helping your fellow may include a comparison of attributes including your race, social standing, intelligence or child-bearing capabilities.
Perhaps he is elderly and you are young. He has already given the world everything he will, while you are just starting.
On the other hand, perhaps you are an elderly philanthropist who will save thousands from poverty and he is a young ne'erdowell who will drain people and harm them.
The principle of equality avoids any such balancing. Huxley makes the point in Evolution and Ethics that there is no human being disinterested enough to be trusted with this kind of cost-benefit analysis. (This is especially true in a lifeboat.) If there was, there would still be no human being intelligent enough to be trusted with this analysis. A principle of equality, strictly applied, is our best guarantee against selfish and even homicidal determinations.
Equality and compassion are not the same thing. In the absence of the slightest shred of compassion, you and I may coldly decide that the safest way for us to coexist is to enforce strict equality. While I cannot usually infer compassion from the fact that you treat me as an equal, I may be able to infer it if you freely treat me better than you treat yourself. Thus, the person who foregoes her share of the bread, the one we secretly would like to be, is most likely to be acting from compassionate motives.
I have touched upon two different approaches I might hypocritically follow in deciding not to share my bread with you. One is the most obviously selfish, and reprehensible to most of us: I am a better human being than you, because I have white skin, or am handsomer, have a better sense of humor, am smarter, etc. Therefore, I will not share my bread.
The other approach is harder to criticize, because it cloaks itself in compassion, though it is not compassionate. This is the utilitarian approach, which claims that if I survive, rather than you, the greatest good will result to the greatest number. I am an American businessman, and you are an Ethiopian farmer. If you live, you will work your farm, feed your family, and have a few more children. If I live, I will found companies, creating tens of thousands of jobs, and I will even devote 1% of my revenues to charity, helping the children of other Ethiopian farmers become healthy and well-educated. Therefore, I will not share my bread.
The fallacy here is that I am balancing putative lives, lives yet unknown, against that of my very real and present companion in the lifeboat. I am lining up fantasy people in rows obediently to shout that I myself must be spared, no matter what becomes of my companion, so I may help them. But their needs are too contingent, too unrelated to those of any actual beings, to outweigh the needs of the other human in the boat with me.
In fact, any judgment that denies help to existing humans based on the needs of future humans seems terribly immoral to me. The argument in such a case is effectively that, if we allow some people to die now, some people not yet born will have a better life. This offends the principle of equality, because we are assuming that the people not yet born are better and more deserving than the people who exist and need our help. This assumption is on the same moral footing as one that holds that some existing group of people must die so that another existing group may live better. It is the ultimate rationale for all genocide.
I am not saying that future lives are unimportant. It seems appropriately careful to act as if we hold the earth in trust for our descendants. But it is a huge leap from this proposition to the one that we must injure existing people to protect our descendants. We can concentrate our behavior as trustees on encouraging population control while distributing resources fairly to people in existence.
Compassion never involves a cost-benefit analysis. I am not saying that compassion should never be tempered by justice, or limited by the possible, nor am I advocating that we should all kill ourselves through compassionate behavior. But the dam does not form part of the river, and the cost-benefit analysis does not form part of compassion.
There is something fine in most of us that recognizes that anyone in danger is of paramount importance. This is the ethic of the emergency room, where we behave no differently if the man with a sucking chest wound is a policeman or a murderer. This is also the ethic of the New Testament, which says that it is more important for the shepherd to seek the one errant sheep than to remain with the 99 safe ones. This is the instinct which leads twelve workers to lose their lives trying to save one in danger. If we cleared away most of the other human superstructure and saved just this, we would do fine. If we eliminated this compassionate instinct while retaining intelligence, trade, politics, and scientific investigation, we would not be recognizably human in the sense in which most of us understand the term.
The earth is our lifeboat. The decisions which must be made in a lifeboat are in fact the decisions which are made every day, by our governments, by ourselves in our daily dealings with others. If we lived every day aware we are in a lifeboat, we would have a clearer understanding of the vitality of global equality and distributive justice at a minimum. And of the importance of compassion to our humanity.