to examine the nature and laws of things to their fullest extent; to seek the ultimate truth through the study of phenomena

To thoroughly investigate the principles and inherent nature of all things in the universe

Unable to find any more words or arguments to defend one's position; having exhausted both one's vocabulary and one's logic.

To find oneself with no more arguments because one's reasoning is weak or flawed; to be silenced by the lack of a convincing explanation.

To have nothing left to say and no logic left to argue; also written as [[词穷理尽|詞窮理盡|ci2 qiong2 li3 jin4]].