Wisdom is the right use of knowledge. To know is not to be wise. Many men know a great deal, and are all the greater fools for it. There is no fool so great a fool as a knowing fool. But to know how to use knowledge is to have wisdom.

—Charles H. Spurgeon

Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.

—Martin Luther King, Jr

I am patient with stupidity but not with those who are proud of it.

—Edith Sitwell

A common mistake that people make when trying to design something completely foolproof was to underestimate the ingenuity of complete fools.

—Douglas Adams

People do not wish to appear foolish; to avoid the appearance of foolishness, they are willing to remain actually fools.

—Alice Walker

Only the wisest and the stupidest of men never change.

—Confucius

Whenever a man does a thoroughly stupid thing, it is always from the noblest motives.

—Oscar Wilde

There are no foolish questions, and no man becomes a fool until he has stopped asking questions.

—Charles Proteus Steinmetz

None is a fool always, everyone sometimes.

—George Herbert

In view of the fact that God limited the intelligence of man, it seems unfair that He did not also limit his stupidity.

—Konrad Adenauer

The ultimate result of shielding men from the effects of folly, is to fill the world with fools.

—Herbert Spencer

Mix a little foolishness with your serious plans: it’s lovely to be silly at the right moment.

—Horace

There are two kinds of fool. One says, “This is old, and therefore good.” And one says, “This is new, and therefore better.”

–John Brunner

Neither man nor woman can be worth anything until they have discovered that they are fools. The sooner the discovery is made the better, as there is more time and power for taking advantage of it.

—William Lamb Melbourne

The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.

—Bertrand Russell