The phrase "fight fire with fire" means to respond to any type of attack with force equal or similar to the attacker; however, the saying originated with a more literal connotation. While using controlled fires dates back thousands of years, the idea was brought to the United States during the 1800's.

Early settlers of the United States had no way of effectively using water for fire fighting. They obviously had no fire trucks or water hoses, and extinguishing fires by carrying water from a creek or river would have been an impossible task. They soon discovered that forest or brush fires could be combated with small controlled fires. These fires, which they dubbed back fires, were set to burn back toward larger uncontrolled fires. As a result, any flammable substances were removed before larger fires reached them, thus depriving the larger fires of fuel. This method, created by using simple logic, protected the settlers' families, homes and crops from grass and forest fires.

It may seem strange or absurd to some people, but back fires, or back burns, are still used in fire fighting today. Passed down for generations over the last two hundred years, it is an effective means of protecting homes and communities from even the most out of control forest fires. When you really think about it, it makes perfect sense. If you eliminate all fuel sources by burning them off, there is nothing left to burn; therefore, the fire has no choice but to extinguish itself.

Presently, the phrase is used in reference to a number of scenarios ranging from military strategies to personal crises. It can refer to physical fights, arguments or getting even with someone for spreading silly rumors. In short, the phrase "fight fire with fire" was created from a literal situation but has come to be used figuratively as well.