June 17, 2013


The human mind’s capacity for accommodating nonsense, quite comfortably, and complete with supporting moonshine, is an awesome thing. Take the adage “The exception that proves the rule.” What? How can an exception to a rule prove it? Ask your average friend or relative that question and the response you’re likely to get is a bemused look. “Well, because the exception would, you know... prove the rule. Don’t you see? It's the exception that proves the rule.” Or the equally lame "Every rule has an exception" as if that proves something, were it true, which it isn't.

If an axiom as plainly suspect as this gets a pass, is it any wonder that more complex cognitive muddles and scams stalk the land?

I mentioned this to my friend Bob Bush once, many years ago. (Bob was chairman of the psychology department at Columbia.) He told me that the phrase had always bothered him too. So much so that he'd looked into it. Turns out “proves” in the saying is an old English usage that meant “tests.” So, in its original form and intent, the exception, instead of validating the rule, calls it into question. That’s better.

Now I’m careful to say “It’s the exception that tests the rule.”

“...that proves the rule,” the person correcting me invariably retorts.

Yeah, that too.