Puzzler's Space

Puzzle 4: The Ruler's Revision: The authority of a ruler is not determined by its length, but by its accuracy.
This is actually two separate statements, which is more obvious in the original language, but by a coincidence, the translations of both use the exact same words.
The first Ruler's Revision refers to measuring devices. A longer ruler is of limited use if a shorter one is more accurate.
The second Ruler's Revision refers to regimes. A regime's authority is not determined by how long it lasted, but by how well its laws and proclamations matched the needs of its people. A regime that cannot provide what its people actually need is failing to use its authority, and so even if it survives, it is in a diminished capacity.
The necessity of both revisions was demonstrated by the fall of Tu Long, when the people stormed the gates while the Emperor was fixated on making a one-mile stick with no markings on it.

Puzzle 5: The only method of knowing is to become a rock oneself. However, in doing so you lose the ability to share your knowledge with others. As such, only teachers who have finished their service have ever pursued this path, choosing it as the conclusion to a lifetime of learning.