Well the principles of society (whatever they are) describe what people do or believe, but ethical principles don't merely describe (or do not describe at all) but they prescribe. They say what people ought to do, not what they do do. For example, a social principle might be what is called psychological egoism. Psychological egoism says: people always (or nearly always) do what they think will benefit them the most. Most people follow their own self-interest. But ethical egoism, not a social principle, but an ethical (normative) principle, and so, prescriptive, says not that people always follow their own self-interest, or do what most benefits them, but rather that is what they ought to do, even if they do not. So psychological egoism is a social principle, but not an ethical principle, because it is descriptive, but not prescriptive; but ethical egoism, on the other hand, is an ethical principle because it is normative or prescriptive, and it is not descriptive. So that is the distinction.
If you need any more help to clarify your own thoughts, please do not hesitate to ask. I am here for you. By the way, I have adopted the motto of the Prince of Wales for what I do on this forum: The motto of the Prince of Wales is, "Ich dien" which, I am sure you know means in German, "I serve". I think it is most appropriate. What do you think?
I have not much seen of you in your sober best. Now we are debating.
After some rough words i would not hesitate to apologise if my phrases have hurt any feelings.
Now, on to the points you have raised.
Sir, the principles of society or in short social principles, are some of derived principles based on observation of human behaviour. I am not suggesting you are wrong or repudiating what you have said above. In fact you have done well to resuscitate your position. Whether ethical principles are descriptive or prescriptive was not the issue at all.
Your assertion that someone else 'thinks' that ethical principle are not social principles was a bad mistake for a reputed debater, which I only pointed out to you, as a debater is duty bound to do. Nothing more.
Having said the above let me pick up from the fresh points you have brought about in this thread.
What is psychological egoism? I have no great problem with the usage except that Ego and egoism is a part of psycholgical studies. So either one can describe it as Individual egoism or Societal/Group egoism. In the case of the latter it would than become psycho-social egoism.
And who said ethical egoism is a social principle. Infact ethical egosim sounds like a misnomer. I can't understand how you bring the rabbit out of the hat. Anyway, the point here is, the bottomline of my thought process is as follows;
Let me deal with the prescriptive aspects of Ethics. It comes under the concept called social norms. An individual, or the majority they accumulate comes under the influence of the society and its norms. One part of which is the ethical rules or standards set by that given society. The adherence to such norms comes from the individuals cognitive ability and the presure that society exerts on the individual.
If you read the works of Baron and Byrne on Social Psychology, they point out three aspects of individual behaviour with the respect to social norms - they being conformity, compliance and obedience.
One result of this observed social phenomenon is the study of Ethics.
When you say ethical principle is not a social principle, you are trying to draw a distinction between an individual's behaviour (for whatever psychological reasons) and society's expected norms of behaviour.
In fact much of the individuals behaviour is moulded by societal norms. Therfore, ethical principles are those principles set by the society and not the individual himself or herself.
I hope this will clear any doubts you have.
Just to add :
Here would clarify, lest someone forgets, that i am a proponent of ethical behaviour in society, and as i may have implied before, the list of ethical principles written by deepthot are like a good ready reckoner for maintaining ethical standards.