Albert Schweitzer — "The greatest tragedy is not death, but life without a purpose."

"The thinking man must oppose all cruel customs, no matter how deeply rooted in tradition and surrounded by a halo. When we have a choice, we must avoid bringing suffering upon other creatures, so far …"

"The greatest challenge of the day is: how to bring about a revolution of the heart, a revolution which has to start with each one of us."

"The greatest revolution of our generation is the discovery that human beings, by changing the inner attitudes of their minds, can change the outer aspects of their lives."

"The greatest good is to do good to others."

"The greatest discovery of all time is that a person can change his future by merely changing his attitude."