Worst Definition of Conscience I've Ever Seen
Conscience is not about disagreeing with the majority, it is about a strong sense of what is right and wrong. It is the nagging feeling you get when you go against what you believe is right or in strong cases the over riding imperitive that prevents you from doing wrong. Your sorry definition would credit criminals with conscience for going against the majorities view that they don't have the right to whatever they want.
Being against the war because most were for it is no evidence of conscience. Most who supported it did so because their consciences thought it was the right thing to do.
Regards,
Mark