"Water can carry a boat, but it can also overturn it" was originally Wei Zhi's "trainable words", and Tang Taizong and Li Shimin often warned future generations in this way, which became Li Shimin's "famous words" for a long time. The meaning of this sentence is straightforward, that is, regard a regime as a "ship" and the people as "water". The meaning of "water can carry a boat, but it can also overturn it" is roughly equivalent to "those who win the hearts of the people win the world, and those who lose the hearts of the people win the world"