How do you decide what is right or wrong? Some people may just say use your common sense. Sensible. The question is whether is makes sense all the time.
If we have a peek as the meaning of common sense in Wikipedia, it has reference to "sound and prudent judgment based on a simple perception of the situation or facts" or "the basic level of practical knowledge and judgment that we all need to help us live in a reasonable and safe way". Watch the key words - judgments, perceptions, knowledge. If we put all these definitions together, common sense is about making decision based on what we perceive as right based on our knowledge and experience.
Do we all have the same knowledge and experience so that our judgments would be common? It would be very risky to answer this question affirmatively. This could be one of the reasons where we have differences of views and thoughts on every issue faced by the societies we live in. Even a society could be further divided into many sub-groups with differing backgrounds and values.
Another issue regarding making common judgment is how do we make such decision? By show of hands? How many hands do we need to count to decide something even in a small city like Kuala Lumpur? I suppose this is where the representation system like election is adopted. Even in such system we have observed many instances where the so called "representatives" may depart from the sense of the people who elected the person in the first place.
What about if the "common sense" is based of values which are totally against the best interests of the society. If thieves are asked whether stealing is right or wrong, don't blame them if they agree that there is nothing wrong with stealing. If corrupt people are asked whether corruption is bad for the society and those who commit corruption should be punished severely, don't blame them if they say that there is nothing wrong with corruption. What more when these corrupt people live in a society where most people know about their evil behaviours but their hands are still being kissed by ordinary people whenever the go around.
Those who believe in revealed religion may fall back on religious teaching in deciding what is right or wrong. However, for others who have differing belief systems, religion do not make sense to them. This has resulted in the separation of religion and state matters in most developed countries.
What is common sense? It appears that what is common may not be that sensible all the time.