Ignorance, when voluntary, is criminal, and a man may be properly charged with that evil which he neglected or refused to learn how to prevent.

Mankind have a great aversion to intellectual labor; but even supposing knowledge to be easily attainable, more people would be content to be ignorant than would take even a little trouble to acquire it

Ignorance, madam, pure ignorance.

All wonder is the effect of novelty on ignorance

You know nothing until you realize that.

The next best thing to knowing something is knowing where to find it.