Significance of the Four Seals
These are said to be the hallmark of the Buddha’s teaching, and it is often said that the mark of a real Buddhist is that he or she accepts these four. Of course, taking refuge is the real entrance to the Buddhist path, and that which serves to distinguish Buddhists from non-buddhists, but in terms of the View, these four statements encapsulate the uniqueness of the Buddha’s teachings and really set the Buddhadharma apart from all other religions and philosophies.
Phillip Stanley has noted that the Four Seals do not appear in the early Tibetan sources on Buddhist terminology, the Mahavyutpatti, Madhyavyutpatti, or Kawa Paltsek's Memoranda on Dharmic Enumerations (chos kyi rnam grangs kyi brjed byang). According to his research, the first Tibetan author to mention the four seals was Longchen Rabjam in his Treasury of Philosophical Tenets. The scholar Butön mentions three seals, an enumeration that is also to be found in Indian sources, such as Shakyaprabha's Prabhāvatī ('od ldan). Tibetan sources do not 
- 1. All produced phenomena are impermanent
- 2. All contaminated products are in the nature of Suffering
- 3. All phenomena are Emptiness
- 4. Nirvana is peace.: