毒どくをもって毒どくを制せいす

expression

fight fire with fire; set a thief to catch a thief

Proverb meaning to use the same harmful means to counter a problem, especially using an evil to defeat another evil.

• 毒どくをもって毒どくを制せいすという言こと葉ばがあるように、時ときには悪わるい手しゅ段だんで悪あくを倒たおすことも必ひつ要ようだ。

  As the saying goes, 'fight fire with fire'; sometimes it's necessary to use bad means to defeat evil.