When an individual’s benefit conflicts with the benefit of society much depends on who the individual happens to be. A criminal wouldn’t be concerned in the slightest - provided he isn’t detected exploiting the honesty of others.
Let’s put it as simply and concretely as possible. I’ll start with the health of a body.
If the subjective goal of an individual is to keep that body alive, then nutritious food is
objectively more conducive to that goal – i.e., more healthy – than rat poison.
We can question, “why do we have the subjective goal of wanting to keep the body alive?” but that is a rather theoretical question (a product of leisure time, which is a good thing, and of folks like us who aren’t constantly
struggling to stay alive). If we were to ask this question to someone starving in the Third World–from what I understand, there is a much lower incidence of suicide in the Third World than in western, industrialized nations-- we might feel ashamed for doing so. The subjective desire to stay alive is nearly universal in human beings, as well as living creatures generally. To this extent, it is an objective human goal (i.e., not particular to me, but to the majority of human beings). And, as stated above, if the goal is to stay alive, there are certain things that
objectively harmonize with this goal (food and water, clothing, shelter), and other things that are objectively harmful to it.
Now to society. The metaphor is simple – a violent criminal is to the health of a society what rat poison is to the health of a human body. This is why the prohibition against violent assault, murder, and theft, is universal in human societies that do not break down into chaos. If a criminal’s subjective whims clash too greatly with the “subjective whims” of other individuals who make up a society – if you want to count “staying alive” as a subjective whim, despite its near universality – then that criminal is forcibly removed from society, for the safety and security of his neighbors.
In connection with this, I do not ask why the Hippocratic oath states, “I will apply dietetic measures for the benefit of the sick according to my ability and judgment; I will keep them from harm and injustice.” Thank God for our health care profession, which does not depend upon any religious belief. If a man is having a heart attack, medical professionals will rush him to a hospital where he will be treated.
You
could have a society where medical professionals rushed to the healthy, in order to beat them senseless and leave them for dead. You could have a society where a fire department’s job was to
start fires, preferably with as many people inside the building as possible. But, again, this would be “legitimate” in the same way that you can have a society where individuals will go to a restaurant to eat garbage and swallow sharp objects, topping it off with an espresso shot of rat poison.
If that were humanity’s preference, it would be a perfectly fine one. But it is not, and there is no danger --belief in God or not – of finding that “eating garbage and swallowing sharp objects” will become the new rage, or that the medical profession will lose its faith and begin doing everything in its power to
worsen the health of its patients; or that the laws of a society will suddenly
mandate violent crime, on pain of imprisonment for those who live too peacefully.
These are the only things that any of us can agree upon, anyway. When we try to go beyond this basic humanistic ethic – talking about whether it is lawful to eat shellfish, or sausage on Good Friday, or non-halal meats, or beef from the sacred cow – consensus breaks down, and we are left-- ironically – with our subjective religious convictions.