Peace cannot be achieved through violence, it can only be attained through understanding.
Ralph Waldo Emerson

Peace is liberty in tranquillity.
Marcus Tullius Cicero

To enjoy good health, to bring true happiness to one's family, to bring peace to all, one must first discipline and control one's own mind. If a man can control his mind he can find the way to Enlightenment, and all wisdom and virtue will naturally come to him.
Buddha

Peace cannot be kept by force; it can only be achieved by understanding.
Albert Einstein

One can not reflect in streaming water. Only those who know internal peace can give it to others.
Lao Tzu