Damon Linker has an interesting post about the problematic history of invocations of “common sense” in American political rhetoric, tracing it from Thomas Paine’s famous book through to McCarthy, George W. Bush, and Glenn Beck.
As long as we’re on the subject, however, it’s worth just making the basic point that common sense tends to be an extremely poor guide to technical issues. It’s common sense that heavy objects fall faster than light ones, and there’s absolutely nothing commonsensical about the correct answer to the Monty Hall Problem. It’s common sense that something called a “strong” dollar must be good, but in fact whether or not it’s good depends on the situation. It’s common sense that when families across the nation tighten their belts, the government should too, but it’s wrong. In fact, the reverse is true and the government ought to get more parsimonious when the private sector is flush, and vice versa. It’s common sense that if you can’t smell or taste or see atmospheric carbon dioxide it must not be a big problem, but it is!
And sensible people recognize that common sense is not, at the end of the day, a particularly reliable guide. It’s common sense that the way to make a heavier-than-air object fly is to imitate birds and have wings that flap. But nobody thinks that anymore, just as nobody today would deny that it’s possible that invisible rays emanating from uranium can give you cancer.