Don't throw the baby out with the bathwater

Don't throw the baby out with the bathwater
= don't lose valuable ideas or things in your attempt to get rid of what is not wanted

替嬰孩洗完澡後，盆裡面那些骯髒的洗澡水是無用之物，須要倒掉。可是，如果因此而將盆裡的嬰孩也一起倒走，則是很錯的事。Don't throw the baby out with the bathwater就是指不要把好東西連同壞東西一起棄掉。