It is better to suffer and stay awake, and it is better to endure pain and think than not to think. - Zweig

Knowledge can only be obtained by positive thinking, and Real knowledge is not obtained from memory. - Tolstoy

To make a person a truly educated person, he must possess three qualities: profound knowledge and thinking habits. And noble sentiments. Not having much knowledge means ignorance; not being accustomed to thinking means rudeness or stupidity; not having noble sentiments means being vulgar. - Chernyshevsky