To me, it feels bad if I think of acting unethically. I define unethical as something that hurts myself and others. I have an image of myself of having standards of behavior. If I go against them, it feels very bad in terms of how I see myself. This is not because society would condemn me, or I would lose esteem in others’ opinion of me, but because I have to live with myself.
Therefore, ethics has to do with conscience. Sociopaths and psychopaths are known not to have a conscience. If they act unethically and hurt others, they may even laugh about it, if they think about it at all. But a person with a well-developed conscience will always prefer the ethical path.