Recently I came across the following line of reasoning.
The reason is because it is COMMON SENSE, which many do not have.
Obviously something goes wrong here as per definition of common sense many people must obey to it/have it. In essence it is the very reverse of a tautology (in the logical sense). How should one classify this error? Is there a specific name to that classification? And with regard to rhetorics, what purpose could such a invalid construction have (such that it can be labeled a fallacy)? Or is it just an oddity of an irrational or confused mind?