To be proud of learning is the greatest ignorance.

-Jeremy Taylor

Not ignorance, but ignorance of ignorance is the death of knowledge.

-Alfred North Whitehead

I am not ashamed to confess that I'm ignorant of what I do not know.

-Cicero

The first step to knowledge is to know that we are ignorant.

-Cecil

There is no darkness but ignorance.

-Shakespeare

There are four causes of ignorance - faith in authority, the power of custom, illusions of sense and the proud delusion of an imagined wisdom.

-Roger Bacon