"The greatest of faults, I should say, is to be conscious of none."
(Thomas Carlyle, 1795-1881)

"There is no sin except stupidity."
(Oscar Wilde)

"There is nothing more fearful than ignorance in action."
(Johann Wolfgang von Goethe, 1749-1832, Criticisms, Reflections and Maxims)

"Those who feel certainty are stupid and those with any imagination or understanding are filled
with doubt and indecision."
(Bertrand Arthur William Russell, 1872-1970)

"To forget one's purpose is the commonest form of stupidity."
(Friedrich Wilhelm Nietzsche)

"What luck for the rulers that men do not think."
(Adolf Hitler)

"Who is more foolish? The fool or the fool that follows it?"
(Alec Guinness)

"Wise men learn more from fools, than fools from the wise."
(Anonymous)