最伟大的战斗不是用武器进行的，而是用思想进行的。
The greatest battles are not fought with weapons, but with ideas.
The true value of a forest cannot be measured in board feet alone.
We must balance the need for energy with the need to protect our planet.
"A picture book is like a small theater."
The advantages found in history seem to be of three kinds， as they result either from the mere situation of the climate and country or from the form of government and of the character of the people， or from those finer principles and morals， which may be called the recommendations of philosophy.