Question

exception that proves the rule Most students love fast food, but Marry is the exception that proves the rule. She tries to eat healthy.

Accepted Answer

If something is different from a general belief or theory, it shows that the belief or theory is true.

Phrase/Idiom	exception that proves the rule
Definition	If something is different from a general belief or theory, it shows that the belief or theory is true.
Example	Most students love fast food, but Marry is the exception that proves the rule. She tries to eat healthy.

Exception Proves Belief Rule General Theory Shows True