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

The ignorant torment themselves more than they do others.

The world is fettered by the chain forged by superstition and ignorance.

Wisdom is prevented by ignorance, and delusion is the result.

Ignorance is when you don't know something and somebody finds it out.

To act without clear understanding, to form habits without investigation, to follow a path all one's life without knowing where it really leads-such is the behavior of the multitude.

I do not pretend to know what many ignorant men are sure of.

Ignorance is the night of the mind, a night without moon or star.

Nothing is more terrible than to see ignorance in action.

A man who has learned little grows old like an ox: his flesh grows, but not his mind.