水至清则无鱼

shuǐ zhì qīng zé wú yú

[when the water is very clear, there will be no fish-one should not demand absolute purity] 源自《大戴礼记》: "水至清则无鱼, 人至察则无徒。 "意谓水太清了, 鱼便不能活。 现用来告诫人们对人对物不可有过高的要求