I'm looking for a BrE or AmE saying that conveys the idea of the Italian saying "chiodo scaccia chiodo", that is "one nail drives out another". The only suggestion I could find is "one problem drives away another" which doesn't appear to be a common one.
Besides, the exact meaning of the Italian proverb is that an issue ( often a heart affair) can be best solved by another issue of similar nature. For instance:
If your girlfriend has left you for someone else and you are sad and depressed, the best solution to your problem is a new girlfriend ( who will help you forget the old one), or if you lose your job you'll best solve your problem by finding a new similar one, but a new job will not solve the "girlfriend" problem and viceversa.
What is the English idiomatic expression used in the examples cited above?
Best Answer
My first thought was fight fire with fire, which is very similar in underlying meaning: like the original saying, it is a description of directly countering one thing with more of the same thing. However, it is virtually always used in the context of a direct conflict, as suggested by the linked definition from Cambridge Dictionaries. I can imagine it being used if your ex is dating someone else in order to make you jealous and someone is advising you to reciprocate, or if your former employer is actively bad-mouthing you to prospective new employers and you are being advised to describe the ex-employer's bad behavior. But I don't think those situations are quite what you have in mind.
So, a couple that I think come closer:
This might be the closest in usage. As the dictionary's examples suggest, it is used in exactly the situations described. My only hesitation is that it doesn't exactly suggest that "getting back on the horse" by dating someone new or getting a new job will make you forget about the previous amour or position, but rather that if you don't "get back out there" right away that the situation will worsen in some way.
This is a little closer in underlying meaning: whatever the problem is, a little bit more of the same thing will cure it. However, as the example sentence above suggests, its overwhelming usage now is for drinking more alcohol to combat a hangover. It is still occasionally used in other situations, however, as for example:
Note: I got called away in the middle of composing this (darn those real-life jobs) and I see that Prodikl has beat me to the punch with hair of the dog and bjmc with fight fire with fire. I'm going to leave the answer as-is at least for now, and up-vote the other answers.