Daily Chinese Idiom Guessing Game
Universally accepted principle; something that is perfectly justified and beyond dispute.
经规范，原则；义正理。天地间历久不变的常道。指绝对正确，不能改变的道理。也指理所当然的事。
《左传·昭公二十五年》夫礼，天之经也，地之义也，民之行也。”
It is a matter of natural law and common sense, as simple and undeniable as the sky above us.