Reaching the limit leads to change; change leads to solution; solution leads to development.

This is a saying from The Book of Changes, meaning that when all means to an extreme are exhausted, it will give rise to a desire for change, while the change will lead to a solution and lasting stability. This is a keen perception of the underlying dynamics of change. In other words, all things are in a state of constant change, and such changes will go in the reverse when they reach the extremes. People should understand this and seize the right time and opportunity to bring about favorable changes and consequently realize smooth and lasting development.

This idea reveals a feature of natural change, that is, all things may reach a bottleneck during the process of change, by which time previously favorable conditions will turn into obstacles hindering further progress. People should adapt to such situations, look for a new path, and make necessary adjustments in order to ensure smooth and steady progress.

Xi Jinping talked about the relationships between change, solution and the lasting effect on a number of occasions, such as the gathering marking the 69th anniversary of the victory in the Chinese People's War of Resistance Against Japanese Aggression and World War II, the 19th General Assembly of the Chinese Academy of Sciences, and the 14th General Assembly of the Chinese Academy of Engineering.

窮則變，變則通，通則久

“窮則變，變則通，通則久”，出自《周易?系辭下》，意為事物達到極限就會發生變化，發生變化才能通順，通順則能長久，這是對事物變化規律的一種認識。也就是說，事物處于不斷的變化之中，并會在極致時朝向對立面轉化。人應該把握這一事物變化規律，在窮極之時尋找變化的契機，促成事物的改變，以實現通順長久的發展。這一理念概括了自然變化的一個基本特征，即萬事萬物發展到一定階段，會遇到瓶頸，原先曾經有利的條件也會成為進一步發展的障礙。這時要主動適應，在變化中尋求新的發展路徑，并通過不斷動態調整，保證工作、事業能夠穩定持續地發展。

習近平在紀念中國人民抗日戰爭暨世界反法西斯戰爭勝利69周年座談會和在中國科學院第十九次院士大會、中國工程院第十四次院士大會上的講話中均提到了“窮則變，變則通，通則久”。