What does the expression «to drive out a wedge with a wedge» mean?
When discussing a complex matter, you may hear the phrase “клин клином вышибают” (“klin klinom vyshybayut”) or "to drive out a wedge with a wedge"." This means that your interlocutor intends to solve the problem with the same means by which it arose.
And there is no metaphor here: In order to split a particularly hard log, sharp iron wedges were driven into the crack made by an ax. If they got stuck, they were driven out with a wider wedge. But, over time, the phrase acquired a figurative meaning. To drive out a wedge with a wedge means to use a means that will help in any case.
There are other expressions with the word ‘wedge’. For example, “вбивать между кем-либо клинья” (“vbibat mezhdu kem-libo klinya”) or "to drive a wedge between someone" means to quarrel with someone and the disapproving “клином не вышибешь” (“klinom ne vyshibesh”) or "you can't drive out a wedge with a wedge" is useful if you can't convince your interlocutor of something.
An English equivalent idiom would be: “To fight fire with fire.”
