The Myth Of Common Sense

If common sense is a methodology other than the use of strict rationality, then it does not exist except as a subjective thing: it is thus not common at all despite its misleading title.  A subjective perception is shared only by happenstance, and it is almost certainly not shared by every person.  Now, if people consistently used the phrase "common sense" in way that identifies common sense with reason itself, then they would not be referring to something subjective, but most uses of the phrase do not truly equate the two.

What many people mean by common sense is nothing more than a subjective sense of personal agreement with an idea based upon intuition or induction.  When pressed, they simply defend a premise by saying "It's just common sense," as if that is all that is necessary to prove a claim.  Beyond this, different people invoke common sense for conflicting ideas that cannot simultaneously be correct.  While disagreement on its own does not prove something is subjective, as aforementioned, common sense cannot be objective unless it is solely a reference to logic itself.

Since common sense is an ambiguous phrase that is often clearly used to denote nothing more than personal persuasion, it is often not being equated with reason.  It follows that nothing about common sense is necessarily common or valid, no matter how puzzled those who like to claim that they side with it might be.  If two people do not use the phrase to refer to the same concept, they are not talking about an accurate set of judgments that are indeed common to begin with.

It is ironic that many who cite common sense as being on their side also claim that few other people seem to have this "common" sense.  They (likely unknowingly) contradict themselves each time they say that common sense has vanished or is disappearing from the world.  Of course, this means that even as they call whatever knowledge they are referring to common, they are actually drawing attention to the fact that they do not think many people share it.  The myth of common sense has dulled its believers to this cognitive dissonance.

Due to its utter subjectivity, common sense, as it is usually defined, has no actual epistemological or practical value.  If someone means to say that everyone has access to logical truths, it is clearer to simply say that everyone is capable of grasping reason to some extent.  If someone means to say that everyone should be familiar with relatively simple scientific phenomena like how gravity interacts with everyday objects, it is clearer to simply sat that everyone can understand everyday scientific events to some extent.  Communicative clarity is the best way to ensure the passage of ideas from one person to another, and yet language is frequently used with far less precision than the topic might call for.