Definition of "it takes one to know one" in English

Proverb

1. Expressing the same underlying character-judgment themes as pot calling the kettle black or set a thief to catch a thief.

   • They hired the most devious scammers they could find and paid them quite well to do some red-team work, because it takes one to know one.

2. A retort to a negative accusation, implying that the accuser shares the fault.

   • Bob: You're an idiot!
   • Tony: Takes one to know one!