I’ve sometimes heard this phrase used when someone is rebutting an example that does not correspond with their argument, but I’ve never really quite grasped how an exception can “prove” or “test” a rule. It’s an exception. It contradicts the rule. Obviously I’m mis-understanding some aspect of the meaning.
The standard explanation is that it refers to the archaic use of ‘prove’, which meant ‘test’. Cannon were proved by having hefty mean belt the crap out of them with hammers for example. If they didn’t crack they were safe to fire. The term ‘proving ground’ was still relatively common early this century. The expression “prove yourself as a man” still hangs on to the archaic use, although I have noticed in the past few years people are writing “prove to yourself that you are a man” or “improve yourself as a man” so that too is losing its meaning, So an exception proved a rule in the truest Socratic tradition of testing the rule against possible contradictory situations. As the definition of ‘prove’ gradually shifted people began to misapply the expression, until today it no longer means what it is intended to.
This sounds plausible enough, and that is certainly a use of prove seen commonly in even moderately old writings. However I don’t know how old the actual expression is.
OK … I suppose that makes sense. So… it’s an exception that’s testing the validity of the rule by existing. If that’s the case, why do people throw out this phrase to the person pointing out a situation in which their argument manifestly does not apply, as if they have sucessfully rebutted the counter-point.
Person A - Women are too emotional to think clearly about legal issues.
Person B - You mean to tell me you think Sandra Day O’Conner of the SCOTUS is too emotional in her judgements?
Person A- Just so! She’s the exception that proves the rule!
What the hell has person A really said, other than a somewhat hollow, “She’s an exception to the norm” assertion?
You got it spot on Astro. All that person A has said is “She’s an exception to the norm”.
The expression is mostly misapplied these days. That’s common enough with cliches that ahve changed their meaning over the years. It’s frighteningly common to hear people say that Suffer the little children" means that children should suffer.
People are misusing the expression. That’s all. It has gone from a reasonable statement to a lame cliche for people whose arguments don’t make sense. Don’t expect sense out of cliches.
I think this is a lot easier to understand when you remember the usage “As a rule…” which means generally or usually. If the only exceptions you can identify are clearly unusual or unlikely, that proves the rule.
So… “The exception proves the rule” means that directly or obliquely referencing that a special leave or exception exists in a situation *** implies*** that rule exists. Fine, I understand now.
Therefore, in this contextual understanding of the phrase, for someone in an argument to reply to a counter-example with this general purpose rhetorical cliche, “that’s the exception that proves the rule”, is non-sensical, unless it is an agreed on fact in the discussion that the counter example is “special”, when in fact the counter arguer is often making precisely the opposite point.
Actually, cannon and rifle barrels are “proved” by firing them with a much larger than recommended powder charge. If they don’t explode when greatly overloaded, they’re safe to fire with a normal charge.
The phrase “the exception that proves the rule” means nothing. I’d just ignore it.
Just for clarification: If I saw something saying “Only on Tuesdays are you allowed to wear hats in the gymnasium,” I could (using the cliche) figure out that you’re not allowed to wear hats on other days?
No, you can figure out that the rule exists without the cliche in that case. If the sign said “Hats allowed on Tuesday” then the cliche indicates that there must be a rule that generally there are no hats allowed. At least, that is how I read it.