I wrote this to GH for his recent post as a musing on the nature of ethics:
The issue with ethics is always the profit motive. If I can profit by being unethical, why shouldn't I?
The answer must be that in some way the 'profit' actually comes at a steeper cost.
The other issue is where one's ethical standards come from in the first place. How do we know they are valid? Subjective ethics do not work because they can only justify how you act, but you cannot use them to criticize the acts of others.
Orthodoxy has answers to these questions, but skepticism makes those answers impotent.
My answers: I value my own ethical integrity and that integrity is worth more to me than any monetary gain or whatever. I also believe that ethics are essentially discovered by mankind as codes that lead to good or bad things for people in society and society in general. We can tell whether an ethic is valid by observing its fruit.
But such experiments, as it would be, are tough to explore in many cases and so we must practically rely on the sustained wisdom of the ages, the sentiments of gifted individuals, and ultimately our own judgement.
The final issue is why should we even care about being ethical at all? Most people care about morality intuitively - an integral part of being human is caring about other people, but I have little to say that could convince a nihilist.