The meaning of the term “common sense” has evolved over the past 2800 years, since Aristotle, of Ancient Greece introduced the term “sensus communis” (Latin meaning “a sense shared by all”). It was Aristotle’s belief that all humans gain information about the world through their five senses and this information is stored as latent knowledge necessary for survival. To Aristotle, common sense was stored at the visceral level, meaning that it organized acquired information in a way that made it intuitive. For example, it was generally perceived as common sense that if you stick your hand in a fire, you will get burned.
During the Age of Enlightenment, philosophers like Kant and Locke regarded common sense as everyday practical knowledge that is immediately accessible to us all, when augmented with some amount of rational thought. The truths contained in the body of knowledge called “common sense” were fundamental to all people with some reasoning ability did not require deep deductive thinking or special knowledge.
In the 18th century, as rational thinking became increasingly popular, “truths” identified as common sense gradually acquired a stronger rational component. When Thomas Paine wrote his pamphlet titled, “Common Sense,” he appealed to his compatriots in the American colonies to reject British rule on the basis that it violated common sense to be ruled by a distant monarch on a tiny island whose interests were opposed to the interests of their colonies.
Today, our conception of common sense contains intuitive knowledge, but has been augmented by a degree of rational deduction and some degree of knowledge. For example, today we might say, ”It’s common sense that if the Federal debt continues to increase, the American way of life will no longer be sustainable.” However, the inclusion of a rational deductive component in this new “enlightened” meaning of common sense renders it less “common.” To those who do not understand the connection between escalating deficits and and monetary inflation, this is not common sense. As the 21st century population in the First World Countries becomes increasingly more educated, differences in intelligence and knowledge are amplified, and consensus on what people would agree to be common sense is diminishing.
Indeed, as the person posing this question has suggested, common sense is different for people in different intelligence strata or with different levels of knowledge. For example, many of those who have never studied chemistry will believe that if they insert their hand in a flame, they will be burned–it’s common sense. They will watch in disbelief as a fire-eater “swallows” fire without suffering burns. But those who have studied chemistry know that they will only feel pain if the fuel burns at a high temperature. When fire-eaters use paraffin oil that burns at low temperatures, those who are schooled in chemistry are not surprised because the adage, “Flames cause pain” is not part of their “common sense.”
