The AskPhilosophers logo.

Logic

How can an exception ever prove a rule?
Accepted:
May 5, 2006

Comments

Thomas Pogge
May 6, 2006 (changed May 6, 2006) Permalink

A rule cannot be proven by there being an exception (a case that violates this rule). So the point of the saying must be that the rule -- understood loosely as a pattern that holds generally or for the most part -- is proved by the fact that a case violating it is recognized as an exception (as exceptional).

For example, you say that John is lazy. I point out that John climbed Wheeler Peak in 1982. You say that the exception proves the rule -- meaning that the exceptionality of the cited counter-instance (I had to go back 24 years to find a good one) confirms your point that John is generally and for the most part lazy.

  • Log in to post comments

Peter Lipton
May 6, 2006 (changed May 6, 2006) Permalink

I think that the expression 'the exception proves the rule' used the word 'proves' in the now perhaps archaic sense of 'tests', which makes the meaning of the expression less paradoxical.

  • Log in to post comments

Thomas Pogge
May 6, 2006 (changed May 6, 2006) Permalink

Here is a third answer focusing on the actual history of the expression: www.worldwidewords.org/qa/qa-exc1.htm

  • Log in to post comments
Source URL: https://askphilosophers.org/question/1153
© 2005-2025 AskPhilosophers.org