He who knows that enough is enough will always have enough.

Lao Tzu

There is no saint without a past, no sinner without a future.

Augustine of Hippo

Doubt is an uncomfortable condition, but certainty is a ridiculous one.

Voltaire

The happiness of your life depends upon the quality of your thoughts.

Marcus Aurelius

He has the most who is content with the least.

Diogenes

Zen has no business with ideas.

D.T. Suzuki