@Alan McDougall,
alan, i thought about this a lot too. i think there are two things involved-the individual's concept of ethics and that of society.
i wondered to myself if it were possible to raise a human being away from all other human beings, like in some of the novels or myths, i.e. tarzan, romulus and remus, would they have a sense of anything being wrong? how would they arrive at that?
i used to define unethical as something that would make me feel shame if i did it, but where does the shame come from? how would one develop shame if there were no other society members to disapprove of us?
i believe social conditioning is what is responsible (or used to gain impunity) for acts like honor killings, and also why some people are inappropriately ashamed of certain acts or even their own bodies.
obviously different societies have different sets of ethics, but there is some common ground where we can agree. i thought for a start there ought to be a formal agreement between all nations. in other words, laws could be put through a computer from all countries and see where we agreed. at the same time we need definitions for those crimes from each, they have to be the same. that isnt the same thing as ethics, it would only be crimes punishable by law, but it might be a start. i chose it because the laws are already in place and we wouldnt need anyone's co-operation to compare.
and even then, people are individuals. universal codes of ethics could never be expressed in a way inclusive enough to guide anyone in all the possible situations they may come across in life. individual ethical judgment calls have to be made.
sorry i havent gotten very far in this. i have developed my own set of ethics, but i would like to know how i did it...and why. it has come about abstractly as a result of my life experiences. but i wouldnt be able to write up a set of rules, i think it is always dependent on a given situation.
i am still struggling with that people on the railroad tracks scenario...