exception that proves the rule
- A form of argument in which the existence of a counterexample to a rule is used to demonstrate the fact that a rule exists.
- (idiomatic) The rare occurrence of a counterexample to a rule, used to underscore that the rule exists.
a form of argument
- “The exception that proves the rule” in Gary Martin, The Phrase Finder, 1997–, retrieved 26 February 2017.
- “Exception that proves the rule” in Michael Quinion, World Wide Words, 14 September 2002.
- The Straight Dope