The phrase 'common sense' has been used by various people in this thread which has prompted me to question the notion and hence the underlying assumptions of those who blindly use it as a means to counter a particular point of view. The phrase common sense for those who liberally use it in this way, is deemed to be an uncontentious notion. Such people, use the phrase as a means to counter a particular point view. After all, surely there must be a some kind of sense that is common to us all, a universal set of 'givens' that transcend party political alliegance and contending ideologies, as akc814ilv alluded to in a previous post on this thread? Anybody who dares question this notion of common sense, is deemed to be a little crazy.

However, I posit that 'common sense' is a highly contentious phrase and merely reflects the prevailing socio-economic conditions in any given historical epoch. Both Karl Marx and later Einstein, were well aware of the nullifying effects of attributing 'common sense' to any argument or debate. For both these great thinkers, common sense was an abstract, and therefore, by extention, a meaningless phrase. Common sense for them (and for me) merely explains aspects in reality that are bound by what are perceptible to the human senses on the surface. For both Marx and Einstein, it was the 'essence' of things that trumped 'the appearance' of things.

In this way, it was possible for scientific discovery to underscore a prevailing set of assumptions, and hence challenge existing bigotries and prejudices. Let me cite some examples of what Marx and Einstein were talking about:

According to physical 'appearances' from the perspective of us on this planet of ours, the earth is flat and does not move. For centuries it was considered to be 'common sense' that the earth was not only stable and fixed within the centre of the universe, but that the sun revolved around the earth. However, thanks to Copernicus and Gallileo we now know that the notion of 'common sense' used in this context, is in reality more akin to 'common idiocy'. Why? Because we know that the reverse is true - the earth is not the centre of the universe and we revolve around the sun.

So in order to discover the truth it is necessary to explore beneath the surface or 'appearance' of things and examine their 'essence'. We do this through scientific research and discovery. It was in this context that Marx famously said: "If essence and appearance coincided then science would become obsolete." Einstein put it like this: "Common sense", he said, "is nothing more than years and years of accumulated prejudice and bigotry."

So I suggest that people always be wary of other people who use the phrase "common sense" in an argument or discussion, because the likelihood is, is that the common sense they speak of, is nothing more than stupidity based on ignorance and prejudice.