Having said this, however, the Treatise of Four Hundred Verses states: “Human beings with few blessings will not raise doubt; those who have doubts can destroy the three worlds of existence.” That is, the cause of our cyclic existence can be damaged if we are able to entertain reasonable doubt about emptiness — Do I lack true existence? Do all phenomena lack inherent existence? It is possible the self does not exist! It is possible all phenomena are empty! When the cause is impaired, we will not remain in samsara for long. If harboring doubt alone is of such great significance, then comprehending and accepting the Middle Way doctrine is even more remarkable.

- Quote from The Four Seals of Dhama, "All Phenomena Lack Self-Existence"