in a quarrel, both parties are to blame
A traditional saying meaning that when a fight or dispute occurs, both sides share responsibility and should be punished or reconciled equally. Often used as a principle in conflict resolution.
The children's fight was settled with both sides being scolded, as in a quarrel both are to blame.
喧嘩両成敗の考え方で、お互いに謝ることになった。
Following the principle that both parties are at fault in a fight, they ended up apologizing to each other.