Courage is to say and do what you feel correct. But I do not totally agree with Mark Twain. It may be not courageous but foolish to offer resitance before a gathering of lunatics. It is well said that angels fear to tread where fools rush in. Foolhardiness is not courage.
In my view, if we want to do something and we have analysed all the positives and negatives, we should do it without caring about the society or others. If we think it is right, we should do it.
It think the word 'courage' admits of so many interpretations.A soldier who displays courage in sacrificing his life for the supreme cause of the motherland is comparable to the one displayed by a person afflicted with terminable disease like cancer with calmness and fortitude.