The Majesty of Calmness is a classic self-help book by William GeorgeJordan that serves as a great success guide. This top self-help book contains this excerpt:

Calmness is the rarest quality in human life. It is the poise of a great nature, in harmony with itself and its ideals. It is the moral atmosphere of a life self-centred, self-reliant, and self-controlled. Calmness is singleness of purpose, absolute confidence, and conscious power, --ready to be focused in an instant to meet any crisis.
The Sphinx is not a true type of calmness, --petrifaction is not calmness, it is death, the silencing of all the energies, while no one lives his life more fully, more intensely and more consciously than the man who is calm.