English equivalent for the expression "only iron can cut iron"

Question

In my native language we have the expression "only iron can cut iron" which means: a force is best confronted with a force of the same nature, or: it takes someone at the same level as someone else to defeat them.

For example:

It wasn't until yesterday that this arrogant man realized he wasn't the best chess player in the world when that guy from the other neighborhood beat him. Only iron can cut iron.

Other examples:

• vaccines that use a weakened form of the virus that causes a disease.
• Using controlled fires to stop a wildfire.

Is there an idiom with the same meaning in English?

Answer 1

In English, we have diamond cut diamond, although I think fight fire with fire is more appropriate in the situation described in the OP.

Fight fire with fire: to use the same methods as someone else in order to defeat them.

[Cambridge English Dictionary]

Answer 2

Both

a force is best confronted with a force of the same nature

and

• Using controlled fires to stop a wildfire.

Are very directly equivalent to fight fire with fire, as per the existing answer.

However

it takes someone at the same level as someone else to defeat them

isn't really the same idiom in English.

Something like set a thief to catch a thief or the related poacher turned gamekeeper both mean using someone's expertise to defeat someone else with the same area of expertise, but note that their aims are not the same: they're not both competing to steal something, instead one is using their knowledge of stealing to prevent the theft.

I can't think of a set phrase that covers all your cases, but the closest for your chess example would be beaten at his own game. This is explicitly losing a competition using your own methods, although the expertise of the victor isn't really explicit.

Answer 3

This is actually a biblical reference:

Iron sharpens iron, So one man sharpens another. Proverbs 27:17 (NASB)

So, at least in English-speaking Judeo-Christian circles, the idiom stands as-is and is relatively well recognized as a biblical proverb. It has the expanded meaning that a person of strong faith can help a person of weaker faith grow by relating their experiences and understanding of biblical truths.

In many circles, it is referenced in more confrontational terms: A faithful Christian may invoke this verse to chastise a fellow Christian who is not faithful to his wife, in the sense that it is his duty to remind the weaker brother that his actions represent a lifestyle of sin - regarded in many Christian circles as an indicator that the person never really accepted the teachings of Jesus Christ, or accepted them and later rejected them.

It is not difficult to see how this idiom evolved over time to more mundane conflicts, such as the better chess player that chastises the arrogant amateur by handily defeating them in a fair match.

Answer 4

There is also the phrase "Steel sharpens steel".

Answer 5

there is a saying common in comic books that says only a god can kill a god

Answer 6

I can't really think of an idiom that means exactly what you are asking for.

The closest thing I can come up with is similar in context:

To be the man, you have to beat the man

which was a catch-phrase popularized by wrestling legend Ric Flair.

However, it means that if you want to be considered the best, you have to beat whoever is currently the best.

Answer 7

In the sense that "a force is best confronted with a force of the same nature", we might say in English

we will hoist him with his own petard

meaning we plan on employing the methods he himself uses in order to "beat him at his own game", an expression which itself could be considered a response to the OP's request.

The expression is much more commonly given as "he was hoisted by his own petard", meaning someone undone by their own plans or actions, without the interference of others, but it can be, and often is, used in the sense of the OP as deliberately employing the particular methods or strategies of another person to defeat them.

For example,

Michigan AFL-CIO President Mark Gaffney said his union will remind voters often between now and the November election that McCain supports national right-to-work measures; voted for free-trade agreements that have sent jobs abroad; and promotes a health care plan that would tax benefits. "Our best approach is going to be his record, which is quite anti-worker, anti-middle class, anti-union," Gaffney said. "We will hoist him on his own petard," Gaffney said.

Another example, another, and another.

It is a particularly English expression because it is derived from Shakespeare's Hamlet and thus has found its way into far fewer languages than the Bible.

As an unrelated note, other commenters and answers have mentioned "set a thief to catch a thief". I agree with this, but at least in American English I have almost always heard this as "it takes a thief to catch a thief" which I think is less about 'this is what we are going to do' and more about 'this is what one would need to do; this is how the world works', and so is closer to what the OP is requesting.