Great spirits have always encountered opposition from mediocre minds. The mediocre mind is incapable of understanding the man who refuses to bow blindly to conventional prejudices and chooses instead to express his opinions courageously and honestly.

-Albert Einstein

"There are two kinds of failures: those who thought and never did, and those who did and never thought."

-Laurence Peter

It is not worth an intelligent man's time to be in the majority. By definition, there are already enough people to do that.

-G.H Peter

Readers are plentiful; thinkers are rare.

-Harriet Martineau

An intelligence test sometimes shows a man how smart he would have been not to have taken it.
-Laurence J. Peter

To repeat what others have said, requires education; to challenge it, requires brains.
-Mary Pettibone Poole

"Perseverance is a great element of success. If you only knock long enough and loud enough at the gate, you are sure to wake up somebody."

Henry Wadsworth Longfellow

"If everyone is thinking alike, someone isn't thinking."

-George Patton

"A mind that is stretched by a new experience can never go back to its old dimensions."

-Oliver Wendell Holmes

"The wise man learns more from the fool than the fool learns from the wise man."

–Marcus Aurelius

"The fool doth think he is wise, but the wise man knows himself to be a fool."

-William Shakespeare

"The older I grow the more I distrust the familiar doctrine that age brings wisdom."

-Henry Mencken

"The philosophy of one century is the common sense of the next."

-Henry Ward Beecher

 "The intelligent man who is proud of his intelligence is like the condemned man who is proud of his large cell."

-Simon Weil