The more one thinks, the more one feels the hopeless immensity of man's ignorance.

It is so easy to hide our ignorance under such expressions as the plan of creation or unity of design, etc., and to think that we give an explanation when we only restate a fact.

Ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science.

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

Truth is by nature self-evident. As soon as you remove the cobwebs of ignorance that surround it, it shines clear.

There are two extremes to be avoided: one is the attitude of contempt toward education, the other is the tragic snobbery of assuming that marching through an educational system is a sure cure for ignorance and mediocrity.