The Four Seals are:
Schools of Buddhism based on the Buddha's teachings accept
the Four Seals of Dharma as the distinction between true
Buddhism and "sorta looks like Buddhism." Further, a teaching
that contradicts any of the Four Seals is not a true Buddhist
teaching.
1. All compounded things are impermanent.
All things are impermanent even a mountain -- certainly a
mountain may remain a mountain for 10,000 years. But even
10,000 years is not "always." The fact is that the world around
us, which seems solid and fixed, is in a state of perpetual flux.
2. All stained emotions are painful.
The Dalai Lama translated this seal "all contaminated
phenomena are of the nature of suffering." The word "stained"
or "contaminated" refers to actions, emotions and thoughts
conditioned by selfish attachment, or by hate, greed and
ignorance.
3. All phenomena are empty.
Another way to say this is that nothing has intrinsic or inherent
existence, including ourselves. This relates to the teaching of
anatman, also called anatta.
4. Nirvana is peace.