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.

死者从未远离我们。他们在我们心中，在我们脑海里，在我们周围。

人生就是走自己选择的路。

真正的挑战不在于解方程，而在于理解解的含义。